Printer, printing program, and printing method

ABSTRACT

A printer includes a print head in which nozzles that form an image by discharging ink are arranged in a plurality of lines. The printer prints out an image on the basis of print form data in which information of layout contents of printing elements that form the content of print is set according to the attribute of each printing element. The printer includes a print form data storage unit, a printing element data storage unit, a print form data selection unit, a printing element data selection unit, and a printing element data insertion unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of U.S. patent application Ser. No.12/070,973 filed on Feb. 22, 2008, which claims priority to JapanesePatent Application No. 2007-043396 filed on Feb. 23, 2007. The entiredisclosures of Japanese Patent Application No. 2007-043396 and U.S.patent application Ser. No. 12/070,973 is hereby incorporated herein byreference.

BACKGROUND

1. Technical Field

The present invention relates to a printer that prints out an image bydischarging ink from nozzles, a printing program, and a printing method.

2. Related Art

For example, in an existing ink jet printer that prints out an image bydischarging ink form nozzles, a process (which is called flushing, orthe like) is performed to discharge ink from all the nozzles at aconstant period of time during the printing process. In this manner, inkis prevented from clogging nozzles that are not used for printing. Theabove flushing technology is, for example, described as an ink jetrecording apparatus in JP-A-2004-106470.

The ink jet recording apparatus described in JP-A-2004-106470 isprovided with a head movement driving portion that reciprocally moves aline ink jet printer head, which performs a one-pass recording mode, inan array direction of its nozzles, that is, in a main scanningdirection, and then executes a head movement process in which driving ofthe head movement driving portion is controlled to move the ink jetprinter head in the array direction of the nozzles and a nozzle positionmodification process in which, in a direction opposite to the headmovement direction at a pitch corresponding to the amount of shift ofthe ink jet printer head at this time, the positions of the nozzles,which discharge ink droplets, are shifted in the ink jet printer head asa whole. In this manner, the positions of the nozzles, which dischargeink droplets, are shifted in the ink jet printer head as a whole, sothat nozzles that do not discharge ink are reduced, and, hence, it isless likely to cause an ink discharge defect in the nozzles.

However, in the existing art described in JP-A-2004-106470, an exclusivemechanism is required for shifting the nozzles, so that there is apossibility that an inconvenience, such as an enlarged size ofapparatus, may occur.

SUMMARY

An advantage of some aspects of at least one embodiment of the inventionis that it provides a printer, a printing program and a printing method,suitable for reducing ink clogging in nozzles that are not used during aprinting process.

A first aspect of at least one embodiment of the invention provides aprinter. The printer includes a print head in which nozzles that form animage by discharging ink are arranged in a plurality of lines. Theprinter prints out an image on the basis of print form data in whichinformation of layout contents of printing elements that form thecontent of print is set according to the attribute of each printingelement. The printer includes a print form data storage unit, a printingelement data storage unit, a print form data selection unit, a printingelement data selection unit, and a printing element data insertion unit.The print form data storage unit stores multiple pieces of print formdata, which include different layout contents of the printing elements,according to the content of usage. The printing element data storageunit stores multiple types of pieces of printing element data, whichcorrespond to pieces of data of the printing elements, according to theattribute of each printing element. The print form data selection unitrandomly selects a piece of print form data, which is used for printing,from among the multiple pieces of print form data stored in the printform data storage unit. The printing element data selection unit selectsa piece of printing element data corresponding to each piece ofinformation of layout content that is set in the selected piece of printform data from among the multiple types of pieces of printing elementdata stored in the printing element data storage unit. The printingelement data insertion unit inserts the selected piece of printingelement data into the selected piece of print form data on the basis ofinformation of the content of print, which is set in the selected pieceof print form data.

According to the above configuration, a piece of print form data israndomly selected from among the multiple pieces of print form data,which include different layout contents of printing elements, the pieceof printing element data having an attribute corresponding to eachlayout content of the piece of print form data that is randomly selectedis inserted, and then printing may be performed. Therefore, whenprinting is continuously performed, printing may be performed byrandomly selecting a piece of print form data every time.

In this manner, it is advantageous in that, during a period whenprinting is continuously performed, as compared to the case whereprinting is performed using the same print form every time, it ispossible to reduce the number of nozzles that are not used or the numberof nozzles that are extremely less frequently used. Thus, for example,when multiple sheets of documents having the same content of usage(purpose), such as direct mail, pay slip, or card history, arecontinuously printed, pieces of print form data, which include differentlayout contents of printing elements sheet by sheet, may be randomlychanged. Thus, it is advantageous in that clogging of ink of nozzlesthat are not used in printing process may be reduced. Particularly, whenthe present aspect is applied to a printer that performs a flushingoperation by which ink is discharged periodically from all the nozzlesin order to prevent ink filled in the nozzles from getting dry, it ispossible to reduce the number of flushing operations, the number ofnozzles used for each flushing operation, or the like, without greatlychanging the configuration of the printer. Furthermore, the number offlushing operations may be reduced in a printing process, so that it ispossible to reduce the time required for printing in comparison with theexisting printer. Particularly, the advantageous effects appear moreremarkably as the number of prints increases.

Here, the print form data are data in which information of layoutcontents of printing elements that form the content of print is setaccording to the attribute of each printing element. The print form datainclude, for example, data that become templates of documentscorresponding to the content of usage (purpose), such as direct mail ordetailed statements, created using word processor software, or the like,data that become templates of arrangement of photographic images toprint out images that are taken by a digital camera, or the like, in apredetermined layout, and the like. In addition, the print form data areformed to include information of a printing region and information oflayout contents of pieces of printing element data, such as text data orimage data, arranged in the printing region (for example, coordinates oflayout positions (regions), layout conditions (character type, charactersize), and the like). Then, when printing is performed, a selectedprinting element is arranged (inserted) in each of the layout regionsand printing is then performed. Thus, it is possible to easily create adocument file or an image file according to the content of usage andthen to print out the file. Hereinafter, the same applies to a printerof a third aspect, a printing program of seventh and eighth aspects anda printing method of ninth and tenth aspects.

In addition, the information of layout content, for text data,corresponds to, for example, character size, character type, characterspacing, margin, and the like, in addition to the coordinate informationof the above described layout content. In addition, the information oflayout content, for image data, corresponds to, for example, informationof resolution, information of palette (limitations of colorrepresentation, and the like), information of type of algorithm when animage is reduced or enlarged to be adjusted to the size of a layoutregion, and the like. Hereinafter, the same applies to a printer of athird aspect, a printing program of seventh and eighth aspects and aprinting method of ninth and tenth aspects.

In addition, the random selection means, for example, in which serialnumbers are assigned to pieces of print form data, a random number thatfalls within the range of the serial numbers is generated, and then apiece of print form data having a serial number equal to the generatedrandom number is selected. Hereinafter, the same applies to a printer ofa third aspect, a printing program of seventh and eighth aspects and aprinting method of ninth and tenth aspects. In addition, the printingelement data are data of printing elements that form the content ofprint, and include, for example, advertising copy and advertisementimage, for direct mail, or the like, table data in which the content ofdetailed statements, such as pay slip or card history, is written, imagedata, document data, table data according to the content of usage otherthan the above. Hereinafter, the same applies to a printer of a thirdaspect, a printing program of seventh and eighth aspects and a printingmethod of ninth and tenth aspects.

Furthermore, the printer according to a second aspect of at least oneembodiment of may be configured so that, in the printer of the firstaspect, the print element data selection unit randomly selects a pieceof printing element data corresponding to each piece of information oflayout content set in the selected piece of print form data from amongthe multiple types of pieces of printing element data that are stored inthe printing element data storage unit. According to the aboveconfiguration, because a piece of printing element data is arrangedaccording to each layout content set in a piece of print form data fromamong pieces of printing element data stored according to the attributeof each printing element, it is advantageous in that it is possible toreduce deviation of nozzle usage frequencies depending on the type ofprinting element.

A third aspect of at least one embodiment of the invention provides aprinter. The printer includes a print head in which nozzles that form animage by discharging ink are arranged in a plurality of lines. Theprinter prints out an image on the basis of print form data in whichinformation of layout contents of printing elements that form thecontent of print is set according to the attribute of each printingelement. The printer includes a print form data storage unit, a printingelement data storage unit, a usage frequency calculation unit, a printform data selection unit, a printing element data selection unit, and aprinting element data insertion unit. The print form data storage unitstores multiple pieces of print form data, which include differentlayout contents of the printing elements, according to the content ofusage and in association with print form nozzle information that isinformation regarding the frequencies of use of the nozzles whenprinting is performed on the basis of the print form data. The printingelement data storage unit stores multiple types of pieces of printingelement data, which correspond to pieces of data of the printingelements, according to the attribute of each printing element. The usagefrequency calculation unit calculates the frequencies of use of thenozzles on the basis of a piece of print form data, into which the pieceof printing element data has been inserted and which has been printedbefore. The print form data selection unit selects a piece of print formdata, which is used for printing, on the basis of the calculatedfrequencies of use from among the multiple pieces of print form datathat are stored in the print form data storage unit. The printingelement data selection unit selects a piece of printing element datacorresponding to each piece of information of layout content that is setin the selected piece of print form data from among the multiple typesof pieces of printing element data stored in the printing element datastorage unit. The printing element data insertion unit inserts theselected piece of printing element data into the selected piece of printform data on the basis of information of the content of print, which isset in the selected piece of print form data.

According to the above configuration, it is possible to select, forexample, a piece of print form data that uses nozzles having lowfrequencies of use or a piece of print form data that refrains fromusing nozzles having high frequencies of use in accordance with thefrequencies of use of the nozzles calculated on the basis of a piece orpieces of print form data, which has been printed before and into whicha piece of printing form data has been inserted. In this manner, becauseprinting may be performed by selecting a piece of print form data thatis appropriate according to the frequencies of use counted from acertain past time up to a present time, in a period when printing iscontinuously performed, as compared to the case where printing isperformed using the same print form every time, it is advantageous inthat it is possible to reduce the number of nozzles that are not used orthe number of nozzles that are extremely less frequently used.

Particularly, when the present aspect is applied to a printer thatperforms a flushing operation as in the case of the first aspect, it ispossible to reduce the number of flushing operations, the number ofnozzles used for each flushing operation, or the like, without greatlychanging the design of the printer. Furthermore, the number of flushingoperations may be reduced in a printing process, so that it is possibleto reduce the time required for printing in comparison with the existingprinter. Particularly, the advantageous effects increase as the numberof prints increases.

Here, the print form nozzle information is information regarding thefrequencies of use of nozzles when a piece of printing element data isinserted into a piece of print form data and then an image is printed.For example, the print form nozzle information is obtained from theaverage value of the frequencies of nozzle usage, or the like, when,according to each piece of information of layout content that is set ineach piece of print form data stored in the print form data storageunit, images of all pieces of printing element data, corresponding tothe layout contents, that are stored in the printing element datastorage unit are printed. For example, it is assumed that, in a certainpiece of print form data, information of layout content is set to eachof four printing elements. In this case, first, the average values ofthe frequencies of nozzles used to print out images of the printingelements, when all types of printing elements corresponding to theattribute of each piece of information of layout content areincorporated for the pieces of information, are calculated.Subsequently, using the average values of the frequencies of use ofnozzles for four pieces of information of layout content, thefrequencies of use of nozzles to print out an (entire) image of thepiece of print form data are calculated. The thus calculated nozzleusage frequencies may be used as the print form nozzle information.Alternatively, from the information of the nozzle usage frequencies, forexample, a distribution of nozzle usage frequencies is checked, and theninformation that represents the distribution of nozzle usage frequenciesmay be used as the print form nozzle information. Hereinafter, the sameapplies to a printing program of an eighth aspect and a printing methodof a tenth aspect.

Furthermore, the printer according to a fourth aspect of at least oneembodiment of the invention may be configured so that, in the printer ofanyone of the first to third aspects, the information of layout contentincludes information of layout position of each printing element andinformation that indicates a layout condition corresponding to theattribute of each printing element, the information of layout positioncorresponding to each piece of printing element is set in advance ineach piece of print form data, the printer further includes a layoutcondition information storage unit, a layout condition informationselection unit and a layout condition information setting unit, thelayout condition information storage unit stores multiple types ofpieces of the layout condition information according to the attribute ofeach printing element, the layout condition information selection unitrandomly selects a piece of layout condition information of a printingelement for information of each layout content set in the selected pieceof print form data from among the multiple types of pieces of layoutcondition information stored in the layout condition information storageunit, the layout condition information setting unit sets the piece oflayout condition information, which is selected by the layout conditioninformation selection unit, to the selected piece of print form data,the printing element data insertion unit inserts the piece of printingelement data, which is selected by the printing element data selectionunit, into the piece of print form data to which the piece of layoutcondition information is set.

According to the above configuration, because a piece of layoutcondition information of a printing element for information of eachlayout content may be randomly selected according to the selected pieceof print form data, it is not necessary to prepare a piece of print formdata for each layout condition. That is, it is only necessary that theprint form data include minimum information, such as information oflayout position, except layout condition information, and it is possibleto greatly reduce the number of types of the information. Thus, it isadvantageous in that it is possible to reduce the memory capacity of astorage unit that stores the print form data.

Here, the layout condition information, for text data, corresponds to,for example, character size, character type, character alignment,character spacing, margin, and the like. In addition, the layoutcondition information, for image data, corresponds to, for example,information of resolution, information of palette (limitations of colorrepresentation, and the like), information of type of algorithm when animage is reduced or enlarged to be adjusted to the size of a layoutregion, and the like.

Furthermore, the printer according to a fifth aspect of at least oneembodiment of the invention may be configured so that, in the printer ofthe third or fourth aspect, the print form nozzle information includesinformation that indicates a distribution of the frequencies of use ofthe plurality of nozzles when printing is performed on the basis of theprint form data.

According to the above configuration, the state of deviation of thefrequencies of use of all the nozzles (to the left, at the center, tothe right, uniformity, or the like) may be recognized from the printform nozzle information. Thus, it is advantageous in that it is possibleto easily and appropriately select a piece of print form data in such amanner that a piece of print form data of which a distribution isappropriate in view of a distribution of overall usage frequenciesrecognized from the calculated frequencies of use is selected.

Furthermore, the printer according to a sixth aspect of at least oneembodiment of the invention may be configured so that, in the printer ofanyone of the third to fifth aspects, the multiple pieces of print formdata are grouped into a plurality of groups according to the content ofthe print form nozzle information and then stored in the print form datastorage unit, the print form data selection unit selects a group ofpieces of print form data on the basis of the calculated frequencies ofuse from among the plurality of groups of pieces of print form data thatare stored in the print form data storage unit, and randomly selects apiece of print form data, which is used for printing, from the selectedgroup.

According to the above configuration, because a piece of print form dataused for printing may be randomly selected from the selected group thatis selected from among the plurality of groups of pieces of print formdata that are stored according to the content of print form nozzleinformation, for example, it is advantageous in that, when the pieces ofprint form data in the same group are continuously used, it is possibleto absorb a variation in frequencies of nozzle usage in each group. Inthis manner, it is advantageous in that it is possible to reduce theoccurrence of deviation of nozzle usage frequencies over all thenozzles.

Furthermore, the printer according to a seventh aspect of at least oneembodiment of the invention may be configured so that, in the printer ofthe sixth aspect, the multiple pieces of printing element data aregrouped into a plurality of groups according to the content of printingelement nozzle information regarding the frequencies of use of thenozzles when an image of the printing element data is printed and thenstored in the printing element data storage unit, the printing elementdata selection unit selects a group of printing element data for eachpiece of information of layout content set in the selected piece ofprint form data on the basis of the calculated frequencies of use fromamong the multiple types of pieces of printing element data stored inthe printing element data storage unit for each layout content, andrandomly selects a piece of printing element data for each layoutcontent from each selected group.

According to the above configuration, because a piece of printingelement data used for printing may be randomly selected from the groupof pieces of printing element data that are stored according to thecontent of printing element nozzle information, for example, it isadvantageous in that, when the pieces of printing element data in thesame group are continuously used, it is possible to absorb a variationin frequencies of nozzle usage in each group. In this manner, because itis possible to reduce the occurrence of deviation of the frequencies ofuse of nozzles to print out each printing element, it is advantageous inthat it is possible to reduce a deviation of nozzle usage frequenciesover all the nozzles.

An eighth aspect of at least one embodiment of the invention provides aprinting program that is used to control a printer. The printer includesa print head in which nozzles that form an image by discharging ink arearranged in a plurality of lines. The printer prints out an image on thebasis of print form data in which information of layout contents ofprinting elements that form the content of print is set according to theattribute of each printing element. The printing program is used toexecute a process on a computer. The process includes randomly selectinga piece of print form data, which is used for printing, from amongmultiple pieces of print form data stored in a print form data storageunit that stores the multiple pieces of print form data, which includedifferent layout contents of the printing elements, according to thecontent of usage, selecting a piece of printing element, data for eachpiece of information of layout content that is set in the selected pieceof print form data from among multiple types of pieces of printingelement data stored in a printing element data storage unit that storesthe multiple types of pieces of printing element data, which correspondto pieces of data of the printing elements, according to the attributeof each printing element, and inserting the selected piece of printingelement data into the selected piece of print form data on the basis ofinformation of the content of print, which is set in the selected pieceof print form data.

With this configuration, when the program is read by the computer and,in accordance with the read program, the computer executes a process,the same function and advantageous effects as in the case of the printerof the first aspect are obtained. Almost all printers, such as ink jetprinters, which are now commercially available, are provided with acomputer system formed by a central processing unit (CPU), a storagedevice (RAM, ROM), an input/output device, or the like, and are able toimplement the above described units using the computer system throughsoftware, so that it is possible to economically and easily implementthe units in comparison with a case where the above units areimplemented by creating an exclusive hardware.

Furthermore, by rewriting a portion of the program, it is possible toeasily upgrade the software for function modifications and/orimprovements. Note that the above aspect may be configured to include aprogram that instructs the computer to execute the functions implementedby the units of the above second aspect or the fourth aspect.

A ninth aspect of the invention provides a printing program that is usedto control a printer. The printer includes a print head in which nozzlesthat form an image by discharging ink are arranged in a plurality oflines. The printer prints out an image on the basis of print form datain which information of layout contents of printing elements that formthe content of print is set according to the attribute of each printingelement. The printing program is used to execute a process on acomputer. The process includes calculating the frequencies of use of thenozzles on the basis of a piece of print form data, into which the pieceof printing element data has been inserted and which has been printedbefore, selecting a piece of print form data, which is used forprinting, on the basis of the calculated frequencies of use from amongmultiple pieces of print form data that are stored in a print form datastorage unit that stores the multiple pieces of print form data, whichinclude different layout contents of the printing elements, according tothe content of usage and in association with print form nozzleinformation that is information regarding the frequencies of use of thenozzles when printing is performed on the basis of the print form data,selecting a piece of printing element data for each piece of informationof layout content that is set in the selected piece of print form datafrom among multiple types of pieces of printing element data stored in aprinting element data storage unit that stores the multiple types ofpieces printing element data, which correspond to pieces of data of theprinting elements, according to the attribute of each printing element,and inserting the selected piece of printing element data into theselected piece of print form data on the basis of information of thecontent of print, which is set in the selected piece of print form data.

With this configuration, when the program is read by the computer and,in accordance with the read program, the computer executes a process,the same function and advantageous effects as in the case of the printerof the third aspect are obtained. Almost all the printers, such as inkjet printers, which are now commercially available, are provided with acomputer system formed by a central processing unit (CPU), a storagedevice (RAM, ROM), an input/output device, or the like, and are able toimplement the above described units using the computer system throughsoftware, so that it is possible to economically and easily implementthe units in comparison with a case where the above units areimplemented by creating an exclusive hardware.

Furthermore, by rewriting portion of the program, it is possible toeasily upgrade the software for functional modifications and/orimprovements. Note that the above aspect may be configured to include aprogram that instructs the computer to execute the functions implementedby the units of anyone of the above fourth to seventh aspects and tolimit data configuration.

A tenth aspect of the invention provides a printing method that is usedto control a printer. The printer includes a print head in which nozzlesthat form an image by discharging ink are arranged in a plurality oflines. The printer prints out an image on the basis of print form datain which information of layout contents of printing elements that formthe content of print is set according to the attribute of each printingelement. The printing method includes randomly selecting a piece ofprint form data, which is used for printing, from among multiple piecesof print form data stored in a print form data storage unit that storesthe multiple pieces of print form data, which include different layoutcontents of the printing elements, according to the content of usage,selecting a piece of printing element data for each piece of informationof layout content that is set in the selected piece of print form datafrom among multiple types of pieces of printing element data stored in aprinting element data storage unit that stores the multiple types ofpieces of printing element data, which correspond to pieces of data ofthe printing elements, according to the attribute of each printingelement, and inserting the selected piece of printing element data intothe selected piece of print form data on the basis of information of thecontent of print, which is set in the selected piece of print form data.In this manner, the same function and advantageous effects as in thecase of the printer of the first aspect are obtained. Note that theabove aspect may be configured so that the units of the above second orfourth aspect are replaced by steps.

An eleventh aspect of at least one embodiment of the invention providesa printing method that is used to control a printer. The printerincludes a print head in which nozzles that form an image by dischargingink are arranged in a plurality of lines. The printer prints out animage on the basis of print form data in which information of layoutcontents of printing elements that form the content of print is setaccording to the attribute of each printing element. The printing methodincludes calculating the frequencies of use of the nozzles on the basisof a piece of print form data, into which the piece of printing elementdata has been inserted and which has been printed before, selecting apiece of print form data, which is used for printing, on the basis ofthe calculated frequencies of use from among multiple pieces of printform data that are stored in a print form data storage unit that storesthe multiple pieces of print form data, which include different layoutcontents of the printing elements, according to the content of usage andin association with print form nozzle information that is informationregarding the frequencies of use of the nozzles when printing isperformed on the basis of the print form data, selecting a piece ofprinting element data for each piece of information of layout contentthat is set in the selected piece of print form data from among multipletypes of pieces of printing element data stored in a printing elementdata storage unit that stores the multiple types of pieces printingelement data, which correspond to pieces of data of the printingelements, according to the attribute of each printing element, andinserting the selected piece of printing element data into the selectedpiece of print form data on the basis of information of the content ofprint, which is set in the selected piece of print form data.

In this manner, the same function and advantageous effects as in thecase of the printer of the third aspect are obtained. Note that theabove aspect may be configured so that the units of anyone of the abovefourth to seventh aspects are replaced by steps and data configurationis limited.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a block diagram that shows the configuration of a printeraccording to a first embodiment of the invention.

FIG. 2 is a partially enlarged bottom view that shows the structure of aprint head.

FIG. 3 is a block diagram that shows the hardware configuration of theprinter.

FIG. 4 is a flowchart that shows a printing process executed in theprinter.

FIG. 5 is a flowchart that shows a process to select a piece of printform data when layout condition information is randomly selected.

FIG. 6 is a flowchart that shows a process to select a piece of printform data when layout condition information is included in the piece ofprint form data in advance.

FIG. 7A is a view that shows an example of a data storage configurationof a print form data storage portion according to a first configuration,and

FIG. 7B is a view that shows an example of a data storage configurationof the print form data storage portion according to a secondconfiguration.

FIG. 8A to FIG. 8D are views, each of which shows an example of first tofourth pieces of searching information.

FIG. 9A to FIG. 9D are views, each of which shows an example of aprinting element.

FIG. 10 is a view that shows a first example of a printing result when apiece of print form data is selected randomly.

FIG. 11 is a view that shows a second example of a printing result whena piece of print form data is selected randomly.

FIG. 12 is a block diagram that shows the configuration of a printeraccording to a second embodiment of the invention.

FIG. 13 is a flowchart that shows a printing process executed in theprinter.

FIG. 14 is a flowchart that shows a process to recognize the frequenciesof nozzle usage in a nozzle usage frequency recognition portion.

FIG. 15 is a view that shows a first example of the size of a characterregion and the size of image regions when a piece of print form data isdivided into three regions.

FIG. 16 is a view that shows a second example of the size of characterregions and the size of image regions when a piece of print form data isdivided into three regions.

FIG. 17 is a view that shows pieces of print form data (example 1 toexample 8).

FIG. 18 is a view that shows the comparison results between a score ofeach region, defined in each of the pieces of print form data shown inFIG. 17, and a threshold value.

FIG. 19A is a view that shows a group configuration when grouping isperformed with respect to CMYK, and

FIG. 19B is a view that shows a group configuration when CMYK areseparated into CMY and K and grouping is performed separately withrespect to each of CMY and K.

FIG. 20A is a view that shows the relationship between a piece ofprinting element data corresponding to an image region and the frequencyof use of nozzles corresponding to each ink color, and

FIG. 20B is a view that shows a group configuration of pieces ofprinting element data corresponding to an image region when grouping isperformed on the basis of the relationship of FIG. 20A.

FIG. 21A is a view that shows an example in which a printing region isdivided in a process to recognize the frequencies of nozzle usage, and

FIG. 21B is a view that shows an example of a moving average that isobtained for each divided region shown in FIG. 21A.

FIG. 22 is a view that shows a first example of the relationship betweena piece of print form data and an average value of nozzle usagefrequencies.

FIG. 23 is a view that shows a second example of the relationshipbetween a piece of print form data and an average value of nozzle usagefrequencies.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS First Embodiment

Hereinafter, a first embodiment of the invention will be described withreference to the accompanying drawings. FIG. 1 to FIG. 11 are views thatshow a first embodiment of a printer, a printing program and a printingmethod according to the first embodiment of the invention. First, theconfiguration of the printer according to the first embodiment of theinvention will be described with reference to FIG. 1. FIG. 1 is a blockdiagram that shows the configuration of the printer 100 according to thefirst embodiment of the invention.

As shown in FIG. 1, the printer 100 includes a usage information inputportion 10, a print form data selection portion 11, a print form datastorage portion 12, a printing element data selection portion 13, and aprinting element data storage portion 14. The usage information inputportion 10 inputs usage information that indicates the usage of aprinted matter. The print form data selection portion 11 randomlyselects a piece of print form data corresponding to the content of usagefrom the print form data storage portion 12, which will be describedlater. The print form data storage portion 12 stores multiple types ofpieces of print form data according to the content of usage. Theprinting element data selection portion 13 selects a piece of printingelement data corresponding to each piece of layout content informationof the selected piece of print form data from the printing element datastorage portion 14, which will be described later. The printing elementdata storage portion 14 stores multiple types of pieces of printingelement data according to the attribute.

The usage information input portion 10 has a function of inputting usageinformation, which is input by a user through an input device (notshown), into the print form data selection portion 11. The usageinformation may be, for example, information corresponding to thecontent of usage of a printed matter, such as direct mail, pay slip, orcard history. Note that, in the present embodiment, the content of usageis input in such a manner that a list of selectable contents of usage isdisplayed in advance, a user is allowed to select anyone of the contentsof usage from among the contents of usage displayed in the list throughan input device 74, which will be described later, and the informationof the selected content of usage is input.

The print form data selection portion 11 has a function of randomlyselecting, on the basis of usage information that is input through theusage information input portion 10, a piece of print form datacorresponding to the usage information from the print form data storageportion 12. Specifically, the print form data storage portion 12 storesmultiple types of pieces of print form data, which include differentlayout contents of printing elements that are set in advance incorrespondence with the content of usage, according to the content ofusage, and the print form data selection portion 11 randomly selects apiece of print form data, which is used for printing, from amongmultiple types of pieces of print form data that belong to the contentof usage corresponding to the input usage information.

In addition, in the present embodiment, the above usage informationincludes information of the number of prints, and the print form dataselection portion 11 randomly selects pieces of print form data for thenumber of prints. For example, when the number of prints (or the numberof sheets printed) is five, the print form data selection portion 11randomly selects five pieces of print for˜data. In addition, the printer100 is also configured, as a first configuration, to randomly determinethe layout condition of each piece of printing element data, which willbe arranged at a layout position indicated by the information of eachlayout content according to the attribute of each printing element, forthe print form data that is selected by the print form data selectionportion 11. In this case, the print form data storage portion 12 storespieces of print form data of which information of layout content doesnot include information of layout condition except the attribute ofprinting element, which will be arranged, and the information of layoutposition, and multiple types of pieces of information of layoutcondition according to the attribute of each printing element. Then, theprint form data selection portion 11, after randomly selecting a pieceof print form data, subsequently generates a random number for eachpiece of information of layout content set in the selected piece ofprint form data and randomly selects a piece of layout conditioninformation.

In the present embodiment, the layout condition information may beselected only for a region into which characters (text) are inserted asa printing element, and two layout conditions, which are font type andfont size, are randomly selected. In addition, the layout conditioninformation of font type is stored in association with second searchinginformation that includes a font type number and an address at whichfont type information corresponding to the font type number is stored.In addition, the layout condition information of font size is stored inassociation with third searching information that includes a font sizenumber, information of length in the vertical direction (hereinafter,referred to as vertical length) of font corresponding to the font sizenumber in a certain font type, and information of font size.

In addition, the printer 100 may be configured, as a secondconfiguration, so that the information of layout condition is includedin information of each layout content that is set in each piece of printform data in advance, and the print form data selection portion 11randomly selects a piece of print form data in which layout conditioninformation is set in advance. In this case, the print form data storageportion 12 stores a piece of print form data in which not onlyinformation of each layout content but also information of layoutcondition of a printing element corresponding to each layout content areset. Then, the print form data selection portion 11 generates a randomnumber and randomly selects a piece of print form data from the printform data storage portion 12.

The print form data storage portion 12, as described above, has afunction of storing multiple types of pieces of print form data, whichinclude different layout contents of printing elements that form thecontent of print, according to the content of usage. In addition, theprint form data has a database configuration so that each of the piecesof print form data is stored, according to the content of usage, inassociation with first searching information that includes a form numberthat is a serial number with respect to all types of pieces of printform data, the vertical length of a region into which characters (text)are inserted, and a storage address of each piece of print form data,and each of the pieces of print form data may be searched through thefirst searching information using a random number generated by the printform data selection portion 11 as a keyword.

In addition, the print form data storage portion 12, when configured asthe above first configuration, stores pieces of print form data that donot include layout condition information and that are associated withthe above pieces of first searching information, and also stores piecesof layout condition information corresponding to the font type andcharacter size in association with the above pieces of second searchinginformation and the above pieces of third searching information. On theother hand, the print form data storage portion 12, when configured asthe second configuration, stores pieces of print form data that includepieces of layout condition information in association with pieces offourth searching information that include a specific form number and astorage address of a piece of print form data corresponding to thespecific form number.

The printing element data selection portion 13 has a function ofselecting a piece of printing element data corresponding to each pieceof information of layout content of each printing element that is set inthe piece of print form data selected by the print form data selectionportion 11 on the basis of the information of layout content from theprinting element data storage portion 14. Here, the information oflayout content according to which each printing element is arranged isset in the piece of print form data according to the attribute of eachprinting element. In the present embodiment, a piece of printing elementdata corresponding to the attribute of information of each layoutcontent is selected from among pieces of printing element data that arestored in the printing element data storage portion 14 in apredetermined sequence or randomly in accordance with the set selectionmode. That is, in the present embodiment, the printing element dataselection portion 13 has two modes as the selection mode: a sequentialselection mode and a random selection mode.

The printing element data storage portion 14 has a function of storingmultiple types of pieces of printing element data according to thecontent of usage of a printed matter and also according to the attributeof each printing element. The attribute of the printing element dataincludes, for example, an advertisement image and an advertising copyfor direct mail, or the like, and a table image (ruled line and text) inpay slip, card history, or the like. Note that, because text sentences,table data, and the like, are mainly composed of text data, regions inwhich these printing elements are arranged are termed as characterregion. In addition, regions in which printing elements composed ofimage data other than text data, such as an advertisement image, aretermed as image region.

In addition, pieces of printing element data, of which all types haveassigned serial numbers, are stored according to the content of usage ofa printed matter and according to the attribute of each printingelement. Furthermore, as shown in FIG. 1, the printer 100 furtherincludes a printing element data insertion portion 15, a print datagenerating portion 16, and a printing portion 17. The printing elementdata insertion portion 15 inserts a piece of printing element data,which is selected by the printing element data selection portion 13,into a piece of print form data. The print data generating portion 16generates print data using the piece of print form data into which eachpiece of printing element data is inserted. The printing portion 17prints out an image on the basis of the print data.

The printing element data insertion portion 15 has a function ofinserting the piece of printing element data that is selected by theprinting element data selection portion 13 into the piece of print formdata that is selected by the print form data selection portion 11.Specifically, the printing element data insertion portion 15 inserts thepiece of printing element data, which is selected for each piece oflayout content information, on the basis of information of layoutposition (coordinates) included in each piece of layout contentinformation and layout condition information included in each piece oflayout content information. In this manner, a piece of print form data,for which each piece of printing element data is inserted into aposition (region) corresponding to each piece of layout positioninformation, is formed.

The print data generating portion 16 has a function of generating printdata to print out an image, formed of printing elements that arearranged at respective layout positions, on the basis of a piece ofprint form data into which each piece of printing element data isinserted by the printing element data insertion portion 15.Specifically, the print data generating portion 16 converts an image,formed of the printing elements, into data that indicate the on/off ofdots that will be formed by the print head 200, which will be describedlater, of the printing portion 17.

Here, the print head 200 applied to the embodiment of the invention willbe described. FIG. 2 is a partially enlarged bottom view that shows thestructure of the print head 200. As shown in FIG. 2, the print head 200has a longitudinal structure extending in a paper width direction ofprint paper used in a so-called line head ink jet printer. The printhead 200 is formed so that four nozzle modules 50, 52, 54, 56 areintegrally arranged so as to form multi-lines and overlap in a printdirection (a direction perpendicular to the nozzle array direction;strictly speaking, a dot print direction of nozzles). The black nozzlemodule 50 includes a plurality of nozzles N (eighteen in the drawing)that exclusively discharge black (K) ink and are arranged in a straightline. The yellow nozzle module 52 includes a plurality of nozzles N thatexclusively discharge yellow (Y) ink and are arranged in a straight linealong the same direction. The magenta nozzle module 54 includes aplurality of nozzles N that exclusively discharge magenta (M) ink andare arranged in a straight line along the same direction. The cyannozzle module 56 includes a plurality of nozzles N that exclusivelydischarge cyan (C) ink and are arranged in a straight line along thesame direction. Note that, when a print head is designed for monochromeprinting, only a black (K) may be used, or, when a print head isdesigned for a high-quality image, six colors of ink or more thatfurther includes light magenta, light cyan, or the like, may be used.

In addition, the above configured print head 200 prints circular dots ona white print sheet of paper by discharging ink, which is supplied intoink chambers (not shown) that are respectively provided for nozzles N1,N2, N3, . . . , through the nozzles N1, N2, N3, . . . , usingpiezoelectric elements, such as piezoactuators (not shown), which areprovided for the respective ink chambers. Moreover, the print head 200is able to print dots having different sizes for each nozzle N1, N2, N3,. . . , by adjusting the amount of ink discharged from the ink chambersby controlling electric voltage applied to the piezoelectric elementsamong multiple levels.

Note that the above described dot means a region formed by ink that isdischarged from one or plurality of nozzles and is adhered on a printingmedium. Moreover, an area of “dot” is not “zero”. The dot, of course,has a certain size (area) and, in addition, dots may have various sizes.However, dots formed by discharging ink do not always become a perfectcircle. For example, when dots are formed in a shape other than perfectcircle, such as ellipse, its average diameter is used as a dot diameter,or a perfect circle equivalent dot having the same area as an area of adot formed by discharging a certain amount of ink is assumed and thediameter of the equivalent dot is used as a dot diameter.

Referring back to FIG. 1, the printing portion 17 is an ink jet printersuch that a predetermined image is formed by a single scanning on amedium (hereinafter referred to as printing medium) used for printing byejecting ink in a dot 42 like shape from the nozzle modules 50, 52, 54,56, which are formed in the print head 200, while moving one of themedium (for example, print paper, or the like) used for printing or theprint head 200 or both. In addition to the above described print head200, the printing portion 17 further includes a paper feed mechanism(not shown) used for moving the printing medium, a print controllermechanism (not shown) that controls discharging of ink of the print head200, and the like.

Note that, as described above, printing that is performed by insertingpieces of printing element data corresponding to pieces of layoutcontent information into a piece of print form data, for which layoutcontent information of each printing element that forms the content ofprint is set, is usually called variable printing. In addition, theprinter 100 is provided with a computer system that implements the usageinformation input portion 10, the print form data selection portion 11,the printing element data selection portion 13, the printing elementdata insertion portion 15, the print data generating portion 16, theprinting portion 17, and the like, on the computer software. Thehardware configuration of the printer 10 a, as shown in FIG. 3,connects, using various internal and external buses 68 formed of a PCI{Peripheral Component Interconnect) bus, and the like, a CPU (CentralProcessing Unit) 60 that executes various controls and processes forprinting, a RAM (Random Access Memory) 62 that constitutes a mainstorage device (Main Storage), a ROM (Read Only Memory) 64 that is aread only storage device, and connects a storage device (SecondaryStorage) 70, such as HDD (Hard Disk Drive) that constitutes the printform data storage portion 12, the printing element data storage portion14, and the like, an output device 72, such as the printing portion 17,a CRT, or an LCD monitor, the input device 74, such as the usageinformation input portion 10, an operation panel, a mouse, a keyboard,or a scanner, and a network L for communication with a print instructiondevice (not shown), or the like, to the buses 68 through an input/outputinterface (I/F) 66.

When the power is turned on, a system program of BIOS, or the like,stored in the ROM 64, or the like, loads various exclusive computerprograms, which are stored in the ROM 64 in advance, onto the RAM 62. Inaccordance with the instructions described in the programs loaded ontothe RAM 62, the CPU 60 uses various resources to execute a predeterminedcontrol and processing, thus implementing the above described functionsthrough the software.

Next, the flow of a printing process in the above configured printer 100will be described with reference to FIG. 4. Here, FIG. 4 is a flowchartthat shows the printing process executed in the printer 100. Theprinting process, as shown in FIG. 4, first proceeds to step 5100, andthe usage information input portion 10 determines whether usageinformation is input from a print instruction terminal, or the like (notshown), such as a personal computer. When it is determined that usageinformation is input (Yes), the input usage information is output to theprint form data selection portion 11 and then the process proceeds tostep 5102. When a negative determination is made (No), the processrepeats a determination process until usage information is input.

When the process proceeds to step 5102, the print form data selectionportion 11 randomly selects a piece of print form data corresponding tothe usage information that is input through the usage information inputportion 10 from the print form data storage portion 12, and then theprocess proceeds to step 5104. In step 5104, the printing element dataselection portion 13 determines whether the random selection mode is setas a selection mode to select printing element data. When it isdetermined that the random selection mode is set (Yes), the processproceeds to step 8106. When a negative determination is made (No), theprocess proceeds to step 8114.

When the process proceeds to step 8106, the printing element dataselection portion 13 randomly selects a piece of information of layoutcontent, which is set in the piece of print form data selected in step8102, from the printing element data storage portion 14. In step 8108,the printing element data insertion portion 15 inserts a piece ofprinting element data selected in step 8106 or in step 8114 into thecorresponding piece of print form data selected in step 8102 on thebasis of a piece of layout content information and layout conditioninformation, and then the process proceeds to step 8110.

In step 8110, the print data generating portion 16 generates print dataon the basis of the piece of print form data into which the piece ofprinting element data is inserted in step 8108, and then the processproceeds to step 8112. In step 8112, the printing portion 17 prints outimages, formed by the piece of printing element data that is inserted instep 8108, on the basis of the print data generated in step 8110, afterwhich a series of processes ends and the process proceeds to step 8100.

On the other hand, in step 8104, when not the random selection mode, butthe sequential selection mode, is set and the process proceeds to step8114, the printing element data selection portion 13 selects a piece ofprinting element data corresponding to a piece of information of layoutcontent set in the piece of print form data selected in step 8102 fromthe printing element data storage portion 14 in a sequence that is setin advance, and then the process proceeds to step 8108.

Furthermore, the flow process to select a piece of print form data wheneach piece of layout condition information is randomly selected will bedescribed with reference to FIG. 5. Here, FIG. 5 is a flowchart thatshows the process to select a piece of print form data when a piece oflayout condition information is randomly selected. In the process toselect a piece of print form data, as shown in FIG. 5, the process firstproceeds to step 8200, and the print form data selection portion 11determines whether usage information is input. When it is determinedthat usage information is input (Yes), the process proceeds to step8202. When a negative determination is made (No), the process repeats adetermination process until usage information is input.

When the process proceeds to step 8202, the print form data selectionportion 11 generates a random number for selecting a piece of print formdata, and then the process proceeds to step 8204. Here, in order togenerate a random number, a known linear congruential method, MT(Mersenne Twister) method, or the like, may be used. When a rate ofgeneration is important, the former linear congruential method is used.When an accuracy of random number is important, the latter MT method isused. Note that the range of a random number is made equal to the rangeof the form number included in the first searching information. Thisalso applies to a process to generate a random number in the followingsteps.

In step 8204, the print form data selection portion 11 searches a pieceof first searching information having the form number equal to therandom number generated in step 8202, and selects (reads out) a piece ofprint form data, which is stored at an address included in the piece offirst searching information retrieved through the searching, from theprint form data storage portion 12, and then the process proceeds tostep 8206. In step 8206, the print form data selection portion 11generates a random number to select font type information, which is oneof the pieces of layout condition information, for information of layoutcontent corresponding to each character region in the information oflayout content set in the piece of print form data that is selected instep 5204, and then the process proceeds to step 5208.

In step 5208, the print form data selection portion 11 searches a pieceof second searching information having the font type number that isequal to the random number generated in step 5206, and selects (readsout) a piece of font type information, which is stored at an addressincluded in the piece of second searching information, from the printform data storage portion 12, and then the process proceeds to step5210. In step 5210, the print form data selection portion 11 generates arandom number to select font size information, which is one of thepieces of layout condition information, for information of layoutcontent corresponding to each character region in the information oflayout content set in the piece of print form data that is selected instep 5204, and then the process proceeds to step 8212.

In step 5212, the print form data selection portion 11 searches a pieceof third searching information having the font size number that is equalto the random number generated in step 5210, and selects (reads out) apiece of font size information, which is stored at an address includedin the piece of third searching information, from the print form datastorage portion 12, and then the process proceeds to step 8214. In step8214, the print form data selection portion 11 compares the verticallength of a layout content of a character region set in the piece ofprint form data selected in step 8204 with the vertical length includedin the font size information that is selected in step 8212, and then theprocess proceeds to step 8216.

In step 8216, the print form data selection portion 11 determines, onthe basis of the result compared in step 8214, whether the verticallength of the character region is greater than the vertical length ofthe selected font size. When the determination is affirmative (Yes), theselected font type information and font size information are set for theselected piece of print form data, after which a series of processesends and the process proceeds to the original process. When a negativedetermination is made (No), the process proceeds to step 8212. Then, arandom number is generated again, and font size information isreselected.

Furthermore, the flow process to select a piece of print form data whenlayout condition information is included in each piece of print formdata in advance will be described with reference to FIG. 6. Here, FIG. 6is a flowchart that shows the process to select a piece of print formdata when layout condition information is included in each piece ofprint form data in advance. In the process to select a piece of printform data, as shown in FIG. 6, the process first proceeds to step 5300,and the print form data selection portion 11 determines whether usageinformation is input. When it is determined that usage information isinput (Yes), the process proceeds to step 5302. When a negativedetermination is made (No), the process repeats a determination processuntil usage information is input.

When the process proceeds to step 5302, the print form data selectionportion 11 generates a random number for selecting a piece of print formdata, and then the process proceeds to step 5304. Here, as in the casedescribed in the above, a linear congruential method, an MT (MersenneTwister) method, or the like, may be used to generate a random number.In step 5304, the print form data selection portion 11 searches a pieceof fourth searching information having a specific form number that isequal to the random number generated in step 5302, and selects (readsout) a piece of print form data, which is stored at an address includedin the fourth searching information, from the print form data storageportion 12, after which a series of processes ends and the processproceeds to the original process.

The operation of the present embodiment will now be described withreference to FIG. 7A to FIG. 11. Here, FIG. 7A is a view that shows anexample of a data storage configuration of the print form data storageportion 12 according to the first configuration, and FIG. 7B is a viewthat shows an example of a data storage configuration of the print formdata storage portion 12 according to the second configuration. Inaddition, FIG. 8A to FIG. 8D are views, each of which shows an exampleof first to fourth pieces of searching information. Moreover, FIG. 9A toFIG. 9D are views, each of which shows an example of a printing element.Furthermore, FIG. 10 and FIG. 11 are views that respectively show firstand second examples of a printing result when a piece of print form datais selected randomly.

When usage information corresponding to a selection instruction from aprint instruction device (not shown), or the like, is input, the usageinformation input portion 1 a, in the printer 10 a, outputs the inputusage information to the print form data selection portion 11 (“Yes” instep S100 in FIG. 4). Here, the usage information includes aninstruction to print out two copies of card history. In addition, aninput determination process of usage information and an output processof input usage information are performed in such a manner that anexclusive program stored in the ROM 64 is loaded onto the RAM 62, andthe loaded program is executed by the CPU.

When the usage information is input from the usage information inputportion 10, the print form data selection portion 11 executes theprocess to randomly select a piece of print form data, which is used forprinting, from among pieces of print form data having the content ofusage corresponding to the input usage information (step S102 in FIG.4). Note that the process to select a piece of print form data isperformed in such a manner that an exclusive program stored in the ROM64 is loaded onto the RAM 62 and then the loaded program is executed bythe CPU 60.

First, the operation of the process to select a piece of print form dataaccording to the first configuration will be described. In this case, asshown in FIG. 7A, the data stored in the print form data storage portion12 are pieces of print form data, in which an overall framework(information of layout content that does not include layout condition)and information of vertical length and horizontal length of eachcharacter region are set, and layout condition information, such as fonttype information and font size information, that determines the layoutcondition of each character region (note that, in FIG. 7A, the layoutcondition information of character alignment is included other than theabove, but it is not used here).

Thus, the print form data selection portion 11 first generates a randomnumber for selecting a piece of print form data by a known MT method(step S202), and searches a piece of first searching information havinga form number that is equal to the generated random number from theprint form data storage portion 12. The first searching information isspecifically configured to include information of a form number, thevertical length of a character region, and the storage address of apiece of print form data, as shown in FIG. 8A. Note that the informationof the vertical length of a character region includes information of thevertical lengths of all the character regions.

Then, the print form data selection portion 11 acquires a piece ofinformation concerning the vertical length of each character regionincluded in the first searching information retrieved through the abovesearching from the print form data storage portion 12, and reads out(selects) a piece of print form data stored in the address that isincluded in the first searching information (step 8204). When the pieceof print form data has been selected, the print form data selectionportion 11 subsequently generates a random number for selecting fonttype information, which is one of the pieces of layout conditioninformation, by a known MT method (step 8206), and searches a piece ofsecond searching information having a font type number that is equal tothe generated random number from the print form data storage portion 12.The second searching information is specifically configured to includeinformation of a font type number and the storage address of font typeinformation, as shown in FIG. 8B.

Then, the print form data selection portion 11 reads out (selects) apiece of font type information, which is stored at an address includedin the second searching information retrieved through the abovesearching, from the print form data storage portion 12 (step 820B inFIG. 5). When the piece of font type information has been selected, theprint form data selection portion 11 generates a random number forselecting font size information, which is one of the pieces of layoutcondition information, by a known MT method (step 8210 in FIG. 5), andsearches a piece of third searching information having a font sizenumber that is equal to the generated random number from the print formdata storage portion 12. Here, a piece of third searching information issearched from among pieces of third searching information correspondingto multiple types of pieces of font size information in association withthe selected font type. In addition, the third searching information isspecifically configured to include information of a font size number, avertical length corresponding to a font type, and the storage address offont size information in association with the font type, as shown inFIG. 8C.

Then, the print form data selection portion 11 reads out (selects) thevertical length included in the third searching information retrievedthrough the above searching and the font size information stored at theaddress that is included in the third searching information from theprint form data storage portion 12 (step 8212 in FIG. 5). When the pieceof font size information has been selected, the print form dataselection portion 11 subsequently compares the vertical length of eachcharacter region, acquired from the first searching information, withthe vertical length corresponding to the font size acquired from thethird searching information (step 5214 in FIG. 5). When the verticallength of each character region is greater than the vertical lengthcorresponding to the font size, the print form data selection portion 11fixes the selected font type and font size for that character region,and then sets these fixed font type information and font sizeinformation for the selected piece of print form data (“Yes” in step5216 in FIG. 5). On the other hand, when the vertical length of eachcharacter region is greater than the vertical length corresponding tothe font size, a random number is generated again to thereby search apiece of third searching information, and the vertical length and fontsize information are selected (step 5212 in FIG. 5).

The above comparison process and the determination process are executedon each character region that is set in each piece of print form data.Next, the operation of the process to select a piece of print form dataaccording to the second configuration will be described. In this case,as shown in FIG. 7B, pieces of print form data stored in the print formdata storage portion 12 correspond to data that include pieces of layoutcondition information, such as overall framework (information of layoutposition of each printing element), the vertical length and horizontallength of each character region, font type information, font sizeinformation, and character position information.

Thus, the print form data selection portion 11 first generates a randomnumber for selecting a piece of print form data by a known MT method(step 8302 in FIG. 6), and searches a piece of fourth searchinginformation having a form number that is equal to the generated randomnumber from the print form data storage portion 12. The fourth searchinginformation is specifically configured to include information of aspecific form number and a storage address of a piece of print formdata, as shown in FIG. 8D.

Then, the print form data selection portion 11 reads out (selects apiece of print form data, which is stored at an address included in thefourth searching information retrieved through the above searching, fromthe print form data storage portion 12 (step 8304 in FIG. 6). In theabove first configuration or the above second configuration, when apiece of print form data is selected, the printing element dataselection portion 13 subsequently executes a process to select a pieceof printing element data in accordance with the selection mode that isset in advance.

Here, when the set selection mode is a random selection mode (“Yes” instep 8104 in FIG. 4), the printing element data selection portion 13generates a random number by a known MT method for information of layoutcontent of each printing element that is set in the selected piece ofprint form data, searches a piece of printing element data having thesame number as the random number from among multiple types of pieces ofprinting element data corresponding to the content of usage of eachpiece of print form data and each attribute indicated by information ofeach target layout content from the printing element data storageportion 14, and then reads out (selects) a piece of printing elementdata retrieved through the above searching from the printing elementdata storage portion 14 (step 8106 in FIG. 4). Note that the process toselect a piece of printing element data (steps 8104 and 8106 in FIG. 4)is performed in such a manner that an exclusive program stored in theROM 64 is loaded onto the RAM 62 and then the loaded program is executedby the CPU 60 (this also applies to step 8114).

Here, the content of usage is card history, so that, for example,information of layout content corresponding to an attribute, such as atable image (ruled line and text) that shows a detailed statement, atable image (ruled line and text) that shows an amount billed,advertisement information (image data), or the like, is set in eachpiece of print form data. A table image or an advertisement imagecorresponding to information of these layout contents is randomlyselected from the printing element data storage portion 14 using arandom number.

On the other hand, when the set selection mode is a sequential selectionmode (“No” in step S104 in FIG. 4), the printing element data selectionportion 13 reads out (selects) a piece of printing element data fromamong multiple types of pieces of printing element data corresponding tothe content of usage of each piece of print form data and the attributeindicated by information of each target layout content in apredetermined sequence that is set in advance from the printing elementdata storage portion 14 (step S114 in FIG. 4). For example, theselection may be made in a sequence (descending sequence or ascendingsequence) of serial numbers that are associated with pieces of printingelement data.

When a piece of printing element data corresponding to the selectedpiece of print form data is selected as described above, the printingelement data insertion portion 15 subsequently inserts the selectedpiece of printing element data on the basis of information of eachlayout content that is set in the selected piece of print form data(step S108 in FIG. 4). Note that the process to insert a piece ofprinting element data is performed in such a manner that an exclusiveprogram stored in the ROM 64 is loaded onto the RAM 62 and then theloaded program is executed by the CPU 60. In addition, specifically, theinsertion of printing element data is performed so that an image of eachselected piece of printing element data for each layout position that isset in each piece of print form data is incorporated into each layoutposition on the basis of the corresponding layout condition, and then apiece of image, in which all the selected pieces of printing elements(table image or advertisement image) are arranged at the set layoutpositions is formed.

For example, as shown in FIG. 1 a, three character regions and two imageregions are set for a piece of print form data. The table image of adetailed statement, the table image of an amount billed and thecharacter image “USE SYSTEMATICALLY” are incorporated into threecharacter regions, and the advertisement images “BEER” and “XX HOTEL”are incorporated into the two image regions, so that a piece of imagethat incorporates therein the three character regions and the two imageregions are generated. By executing the above process to select a pieceof print form data, in the process to select a piece of printing elementdata and in the process to insert a piece of printing element data forthe number of prints (here, two copies) specified in the usageinformation, two sheets of pieces of print form data (image data), intowhich pieces of printing element data, which are selected randomly or ina predetermined sequence, are inserted respectively into the randomlyselected pieces of print form data, are generated.

For example, the second image is formed so that, as shown in FIG. 11,the size and layout content of each character region and each imageregion are different from one another and, for the table image of adetailed statement, font type, font size and the vertical length andhorizontal length of each character region are different from oneanother. That is, two sheets of pieces of print form data, having thesame purpose of usage but having different layout contents of printingelements, are generated. The print data generating portion 16 convertsthe generated two sheets of pieces of print form data into data thatrepresent on/off of each pixel to thereby generate print data of aformat that may be interpreted by the printing portion 17 (step S110 inFIG. 4). Note that the process to generate print data is performed insuch a manner that an exclusive program stored in the ROM 64 is loadedonto the RAM 62 and then the loaded program is executed by the CPU 60.

When the print data have been generated, the printing portion 17sequentially prints out two images that are formed by the insertedprinting elements on printing media on the basis of the above two sheetsof pieces of print data (step S112 in FIG. 4). Note that the printingprocess is performed in such a manner that an exclusive program storedin the ROM 64 is loaded onto the RAM 62, the loaded program is executedby the CPU 60, and then the output device 72 (the hardware of theprinting portion 17, such as print head 200) is controlled on the basisof print control signals from the CPU 60.

That is, as shown in FIG. 10 and FIG. 11, because two images havingdifferent layout contents of printing elements (particularly, layoutpositions) are printed, there is a possibility that nozzles that are notused for printing the first sheet may be used for printing the secondsheet. Here, the number of prints is two; however, when a greater numberof prints are printed, the layout position of each printing elementchanges randomly sheet by sheet. Thus, the number of nozzles that arenot used will be further reduced.

Here, the amount of ink discharged to prevent ink from clogging innozzles will be described. Generally, a minimum standard amount ofdischarged ink required in order to prevent nozzle clogging, isdetermined. This minimum standard is determined as a criterion in whichm or more number of dots printed in n seconds is required. Thus, whenprinting on print paper is considered, it is not particularly necessaryto make the number of dots printed per one sheet of printed result be mor above. For example, when the printer 100 can print p sheets per nseconds, it is only necessary for all the nozzles to print m or morenumber of dots per p sheets. Particularly, a line head printer, whichcompletes printing by a single scanning, has a head arranged in a lineabove a sheet of paper in order to print out at high speed, so thatmultiple sheets of paper may be printed per one second. In addition, nseconds range from a few seconds to several tens of seconds, so that itis sufficient to perform printing of standard m or more number of dotsin units of multiple sheets of paper.

That is, when printing is continuously performed on multiple sheets ofpaper, because layout positions of printing elements are randomlychanged sheet by sheet, it is possible to improve probability by whichthe number of dots formed by each nozzle per n seconds is equal to orlarger than m. As described above, the printer 100 according to thefirst embodiment is able to randomly select a piece of print form data,which is used for printing, from among multiple types of pieces of printform data in which layout contents are set in advance sheet by sheet forthe specified number of prints according to the content of usage.

In addition, according to the first configuration, it is possible to notonly randomly select a piece of print form data that include informationof layout condition corresponding to the attribute of each printingelement from among multiple types of pieces of print form data, but alsorandomly select the layout condition of each printing element. On theother hand, according to the second configuration, it is possible torandomly select a piece of print form data that include information oflayout position corresponding to the attribute of each printing elementand layout condition information of each printing element from among themultiple types of pieces of print form data.

In addition, for the thus randomly selected piece of print form data, itis possible to select a piece of printing element data corresponding toeach piece of information of layout content from among the multiplepieces of printing element data randomly or in a predetermined sequence.Furthermore, it is possible to insert the selected piece of printingelement data into the piece of print form data and generate print datausing the inserted piece of print form data, and then it is possible toprint out an image on the basis of the print data.

As described above, because an image that randomly changes its layoutcontents for each print may be printed, it is possible to improve thefrequencies of use of nozzles of the print head 200 (reduce nozzles thatare not used). In addition, according to the above first configuration,because layout condition may also be randomly selected, it is possibleto reduce storage capacity for print form data.

On the other hand, according to the second configuration, because apiece of print form data used for printing is randomly selected fromamong pieces of print form data in which layout condition is set, it ispossible to select a piece of print form data used for printing in asingle selection process. In this manner, for example, when a largenumber of prints are performed continuously, it is possible to executethe process more quickly as compared to the above first configuration.In the above first embodiment, the print form data selection portion 11may be regarded as the print form data selection unit of the firstaspect, the print form data storage portion 12 may be regarded as theprint form data storage unit of anyone of the first, eighth and tenthaspects and the layout condition information storage unit of the fourthaspect, the printing element data selection portion 13 may be regardedas the printing element data selection unit of the first aspect or thesecond aspect, the printing element data storage portion 14 may beregarded as the printing element data storage unit of anyone of thefirst, second, third, eighth and tenth aspects, and the printing elementdata insertion portion 15 may be regarded as the printing element datainsertion unit of the first aspect.

Moreover, in the above first embodiment, the processing function of theprint form data selection portion 11 to select layout conditioninformation may be regarded as the layout condition informationselection unit of the fourth aspect, and the processing function of theprint form data selection portion 11 to set the selected layoutcondition information into print form data may be regarded as the layoutcondition information setting unit of the fourth aspect. Furthermore, inthe above first embodiment, the step S102 of FIG. 4 may be regarded asthe print form data selection step of the eighth aspect or the tenthaspect, the steps S104, S106, S114 may be regarded as the printingelement data selection step of the eighth aspect or the tenth aspect,and the step S108 may be regarded as the printing element data insertionstep of the eighth aspect or the tenth aspect.

Second Embodiment

Next, a second embodiment of the invention will be described withreference to the accompanying drawings. FIG. 12 to FIG. 23 are viewsthat show a second embodiment of a printer, a printing program and aprinting method according to the invention.

First, the configuration of the printer according to the secondembodiment of the invention will be described with reference to FIG. 12.FIG. 12 is a block diagram that shows the configuration of a printer 300according to the second embodiment of the invention. The presentembodiment differs from the first embodiment in that, on the basis ofthe frequencies of nozzles used for print form data that are printed fora past predetermined period, the frequencies of use of nozzles in thepredetermined period are recognized, and a piece of print form data usedfor printing is selected on the basis of the recognized content. Inaddition, the present embodiment also differs from the first embodimentin that each piece of print form data is stored in association with theaverage frequencies of use of nozzles when printing is performed usingthe piece or print form data, and each piece of printing element data isstored in association with the frequencies of use of nozzles when animage of the piece of printing element data is printed.

Hereinafter, the portions that differ from those of the first embodimentwill be described in detail, and the same reference numerals areassigned to the overlapping portions and the description thereof will beomitted. First, the configuration of the printer according to the secondembodiment of the invention will be described with reference to FIG. 12.FIG. 12 is a block diagram that shows the configuration of the printer300 according to the second embodiment of the invention.

As shown in FIG. 12, the printer 300 includes the usage informationinput portion 10, a nozzle usage frequency recognition portion 3D, anozzle usage frequency information storage portion 31, a print form datagroup selection portion 32, a print form data storage portion 33, aprint form data selection portion 34, a printing element data selectionportion 35, and a printing element data storage portion 36. The nozzleusage frequency recognition portion 30 recognizes the frequency of useof each nozzle. The nozzle usage frequency information storage portion31 stores information of nozzle usage frequencies for a piece of printform data that has been printed before. The print form data groupselection portion 32 selects a group of pieces of print form datacorresponding to the recognized content from the print form data storageportion 33, which will be described later. The print form data storageportion 33 stores pieces of print form data in association withinformation regarding the frequencies of use of nozzles. The print formdata selection portion 34 selects a piece of print form data used forprinting from the selected group of pieces of print form data. Theprinting element data selection portion 35 selects a piece of printingelement data corresponding to the selected piece of print form data fromthe printing element data storage portion 36, which will be describedlater. The printing element data storage portion 36 stores pieces ofprinting element data in association with information regarding thefrequencies of use of nozzles.

The nozzle usage frequency recognition portion 30 has a function ofrecognizing the frequencies of use of nozzles in a predetermined periodon the basis of usage frequency information of each nozzle for a pieceof print form data that has been printed in the predetermined periodbefore and which is stored in the nozzle usage frequency informationstorage portion 31. Specifically, on the basis of information of thefrequencies of use of nozzles in a past predetermined period, the movingaverage of the frequencies of use of the nozzles of the print head 200is calculated (for each ink color), and a distribution (distribution forall ink colors) of the frequencies of use of nozzles in a predeterminedperiod is recognized from the calculated moving average. For example, itis recognized that the frequencies of nozzle usage is high or low to theleft in the nozzle array direction of the print head 200.

Here, the frequencies of nozzle usage may be, for example, obtained bycalculating information (projection information) that indicates thetotal number of dots in each 71 image line in a printed target image forevery image of each color using a piece of print form data that has beencolor converted into CMYK. The number of dots formed by each nozzle maybe obtained from this projection information. The nozzle usage frequencyinformation storage portion 31 has a function of storing the frequenciesof nozzle usage that are calculated by a nozzle usage frequencycalculation portion 37, which will be described later, for a piece ofprint form data used for printing in association with a period of timeduring which the piece of print form data is printed. Here, the nozzleusage frequencies are calculated using the number of printing dots(projection information) of nozzles corresponding to each ink color.

The print form data group selection portion 32 has a function ofselecting a group corresponding to the content recognized by the nozzleusage frequency recognition portion 30 from among a plurality of printform data groups that are grouped according to the content ofinformation regarding the nozzle usage frequencies for each piece ofprint form data (hereinafter, referred to as print form nozzleinformation) and that are stored in the print form data storage portion33.

The print form data storage portion 33, as described above, has afunction of storing multiple types of pieces of print form data, whichare grouped according to the content of print form nozzle information,according to the content of usage. Note that, in regard to groups ofpieces of print form data, serial numbers are assigned to the groupsaccording to the content of usage of a printed matter, and, furthermore,in each group, serial numbers are assigned to pieces of print form data.Thus, the print form data storage portion 33 has a databaseconfiguration that uses these serial numbers as searching information.

The print form data selection portion 34 has a function of selecting apiece of print form data, which is used for printing, in a predeterminedsequence or randomly from the group selected by the print form datagroup selection portion 32 in accordance with a selection mode that isset in advance. That is, the print form data selection portion 34, inthe present embodiment, has two modes as the selection mode: asequential selection mode and a random selection mode.

The printing element data selection portion 35 has a function ofselecting a printing element data group corresponding to each piece oflayout content information and each piece of print form nozzleinformation on the basis of information of layout content of eachprinting element that is set in each piece of print form data selectedby the print form data selection portion 34 and each piece of print formnozzle information from the printing element data storage portion 36.The printing element data selection portion 35 also has a function ofselecting a piece of printing element data corresponding to the piece oflayout content information from the group of pieces of printing elementdata that is selected in the selection mode that is set in the printform data selection portion 34. That is, in the printing element dataselection portion 35, when the sequential selection mode is set, a pieceof printing element data will be selected in a predetermined sequence,and, when the random selection mode is set, a piece of printing elementdata will be selected randomly.

The printing element data storage portion 36 has a function of storingmultiple types of pieces of printing element data that are groupedaccording to the content of information regarding the frequencies ofnozzle usage when an image of each piece of printing element data isprinted (hereinafter, referred to as printing element nozzleinformation) according to the content of usage of a printed matter andalso according to the attribute of each printing element. Note that, inregard to the pieces of printing element data stored in the printingelement data storage portion 36, serial numbers are assigned to groupsof pieces of printing element data according to the content of usage ofa printed matter and also according to the attribute of each printingelement, such as character or image, and, furthermore, in each group,serial numbers are assigned to pieces of printing element data. Thus,the printing element data storage portion 36 has a databaseconfiguration that uses these serial numbers as searching information.

Furthermore, as shown in FIG. 12, the printer 300 further includes theprinting element data insertion portion 15, the print data generatingportion 16, the printing portion 17, and the nozzle usage frequencycalculation portion 37. The printing element data insertion portion 15inserts a piece of printing element data that is selected by theprinting element data selection portion 13 into a piece of print formdata. The print data generating portion 16 generates print data usingthe piece of print form data into which a piece of printing element datais inserted. The printing portion 17 prints out an image on the basis ofthe print data. The nozzle usage frequency calculation portion 37calculates the frequencies of use of the nozzles of the print head 200for print data on the basis of the print data.

The nozzle usage frequency calculation portion 37 has a function ofcalculating the frequencies of use of the nozzles of the print head 200on the basis of print data with which printing has been performed by theprinting portion 17. Specifically, projection information is calculatedfrom print data that are generated by the print data generating portion16. Here, the projection information is information concerning thenumber of dots formed by each nozzle when an image of a piece of printform data, into which a piece of printing element data is inserted, isprinted.

In addition, the printer 300, as well as the printer 100 according tothe first embodiment, is provided with a computer system, which isequivalent to the one shown in FIG. 3, that implements the usageinformation input portion 10, the nozzle usage frequency recognitionportion 30, the nozzle usage frequency information storage portion 31,the print form data group selection portion 32, the print form dataselection portion 34, the printing element data selection portion 35,the printing element data insertion portion 15, the print datagenerating portion 16, the printing portion 17, the nozzle usagefrequency calculation portion 37, and the like. The hardwareconfiguration of the printer 300, as shown in FIG. 3, connects, usingvarious internal and external buses 68 formed of a PCI (peripheralComponent Interconnect) bus, and the like, among a CPU (CentralProcessing Unit) 60 that executes various controls and processes forprinting, a RAM (Random Access Memory) 62 that constitutes a mainstorage device (Main Storage), a ROM (Read Only Memory) 64 that is aread only storage device, and connects a storage device (SecondaryStorage) 70, such as HDD (Hard Disk Drive) that constitutes the nozzleusage frequency information storage portion 31, the print form datastorage portion 33, the printing element data storage portion 36, andthe like, the output device 72, such as the printing portion 17, a CRT,or an LCD monitor, the input device 74, such as the usage informationinput portion 10, an operation panel, a mouse, a keyboard, or a scanner,and a network L for communication with a print instruction device (notshown), or the like, to the buses 68 through an input/output interface(I/F) 66.

Then, when the power is turned on, a system program of BIOS, or thelike, stored in the ROM 64, or the like, loads various exclusivecomputer programs, which are stored in the ROM 64 in advance, onto theRAM 62. In accordance with the instructions described in the programsloaded onto the RAM 62, the CPU 60 uses various resources to execute apredetermined control and processing, thus implementing the abovedescribed functions through the software.

Next, the flow of a printing process in the above configured printer 300will be described with reference to FIG. 13. Here, FIG. 13 is aflowchart that shows a printing process executed in the printer 300. Theprinting process, as shown in FIG. 13, first proceeds to step S400, andthe usage information input portion 10 determines whether usageinformation is input from a print instruction terminal, or the like (notshown), such as a personal computer. When it is determined that usageinformation is input (Yes), the input usage information is output to thenozzle usage frequency recognition portion 30 and then the processproceeds to step S402. When a negative determination is made (No), theprocess repeats a determination process until usage information isinput.

When the process proceeds to step S402, the nozzle usage frequencyrecognition portion 30 recognizes the frequencies of use of the nozzlesof the print head 200 in a past predetermined period on the basis ofnozzle usage frequency information in the past predetermined period,stored in the nozzle usage frequency information storage portion 31, andoutputs the recognized content and the usage information to the printform data group selection portion 32, and then the process proceeds tostep 8404.

In step 8404, the print form data group selection portion 32 selects aprint form data group corresponding to the input usage information andthe content recognized in step 402 from the print form data storageportion 33, and then the process proceeds to step 8406. In step 8406,the print form data selection portion 34 determines whether the randomselection mode is set as the selection mode. When the random selectionmode is set (Yes), the process proceeds to step 8408. When a negativedetermination is made (No), the processes proceeds to step 8420.

In step 8408, the print form data selection portion 34 randomly selectsa piece of print form data used for printing from the group of pieces ofprint form data selected in step 8404, and then the process proceeds tostep 8410. In step 8410, the printing element data selection portion 35selects a group of pieces of printing element data corresponding topieces of layout content information and pieces of print form nozzleinformation that are set in the piece of print form data selected instep 8408 from the printing element data storage portion 36, andrandomly selects a piece of printing element data corresponding to eachpiece of layout content information from each selected group, and thenthe process proceeds to step 8412.

In step 8412, the printing element data insertion portion 17 inserts apiece of printing element data selected in step 5410 or in step 5422into the corresponding piece of print form data selected in step 5408 onthe basis of each piece of layout content information and each piece oflayout condition information, and then the process proceeds to step5414. In step 8414, the print data generating portion 16 generates printdata on the basis of the piece of print form data into which each pieceof printing element data is inserted in step 5412, and then the processproceeds to step 5416.

In step 8416, the printing portion 17 prints out an image, formed by thepiece of printing element data that is inserted in step 5412, on thebasis of the print data generated in step 5414, and then the processproceeds to step 5418. In step 5418, the nozzle usage frequencycalculation portion 37 calculates the frequencies of use of the nozzlesof the print head 200 for print data, which is printed in step 416, onthe basis of the print data, and information of the calculated nozzleusage frequencies is stored in the nozzle usage frequency informationstorage portion 31, after which a series of processes ends and theprocess proceeds to step 5400.

On the other hand, in step 5406, when not the random selection mode, butthe sequential selection mode is set, and the process proceeds to step5420, the print form data selection portion 34 selects a piece of printform data used for printing from the print form data group selected instep 5404 in a predetermined sequence, and then the process proceeds tostep 5422. In step 5422, the printing element data selection portion 35selects a group of pieces of printing element data corresponding to apiece of layout content information and a piece of print form nozzleinformation that are set in the piece of print form data selected instep 420 from the printing element data storage portion 36 in a sequencethat is set in advance, and randomly selects a piece of printing elementdata corresponding to each piece of layout content information from eachselected group, and then the process proceeds to step 5412.

Furthermore, the flow of nozzle usage frequency recognition processexecuted in the nozzle usage frequency recognition portion 30 will bedescribed with reference to FIG. 14. Here, FIG. 14 is a flowchart thatshows the process to recognize the frequencies of nozzle usage in thenozzle usage frequency recognition portion 30. In the nozzle usagefrequency recognition process, as shown in FIG. 14, the process firstproceeds to step 8500, and the nozzle usage frequency recognitionportion 30 acquires a piece of nozzle usage frequency information forprint data that have been printed in a past predetermined period fromthe nozzle usage frequency information storage portion 31, and then theprocess proceeds to step 8502.

In step S502, the nozzle usage frequency recognition portion 30 dividesa printing region of each piece of print data that has been printed in apast predetermined period into three so that the adjacent regions halfoverlap each other, and then the process proceeds to step 8504. In stepS504, the nozzle usage frequency recognition portion 30 calculates theaverage value of the nozzle usage frequencies for each of the regions(all for a predetermined period) that are divided in step S502, and thenthe process proceeds to step 8506.

In step 8506, the nozzle usage frequency recognition portion 30 comparesthe average values of the nozzle usage frequencies of the regions,calculated in step 8504, to one another, and then the process proceedsto step 8508. In step S508, the nozzle usage frequency recognitionportion 30 recognizes, on the basis of the comparison result in step8506, the region that has the lowest average value of nozzle usagefrequencies as the distribution of three groups “to left”, “uniformity”and “to right”, after which a series of processes ends and the processproceeds to the original process.

In the present embodiment, the recognition of the above distribution ismade in such a manner that a predetermined threshold is compared withthe average value of each region and, when only the average value of theleft region is equal to or lower than the threshold value, it isdetermined that the distribution is deviated to the left, only theaverage value of the right region is equal to or lower than thethreshold value, it is determined that the distribution is deviated tothe right, and other than those, it is determined that the distributionis uniform.

The operation of the present embodiment will now be described withreference to FIG. 15 to FIG. 23. First, grouping of pieces of print formdata will be described with reference to FIG. 15 to FIG. 19B.

FIG. 15 is a view that shows a first example of the size of a characterregion and the size of image regions when a piece of print form data isdivided into three regions. FIG. 16 is a view that shows a secondexample of the size of character regions and the size of image regionswhen a piece of print form data is divided into three regions. FIG. 17is a view that shows pieces of print form data (example 1 to example 8).FIG. 18 is a view that shows the comparison results between a score ofeach region, defined in each of the pieces of print form data shown inFIG. 17, and a threshold value. FIG. 19A is a view that shows a groupconfiguration when grouping is performed with respect to CMYK, and FIG.19B is a view that shows a group configuration when CMYK are separatedinto CMY and K and grouping is performed separately with respect to eachof CMY and K.

As is described in the above first embodiment, in each of the pieces ofprint form data, pieces of printing element data for insertion aregrouped into data that are inserted into a character region, which is aninsertion region for a table image, a text sentence, or the like, anddata that are inserted into an image region, which is an insertionregion for an advertisement image, a photographic image, or the like.Normally, character images are often black and, therefore, the frequencyof use of K ink increases in the character region. On the other hand,various colors are used in the image region, so that the frequencies ofuse of C, M, Y and K inks increase. Accordingly, through the presence orabsence of a character region and an image region and the relationshipof the arrangement between a character region and an image region in aprint form, it is possible to estimate where the percentages of use ofC, M, Y, and K inks are high or are low.

In addition, for example, the frequencies of use of C, M, Y, and K inksare high when a large number of advertisement images are printed, andthe averages of the frequencies of use of colors are progressivelyuniform. On the contrary, in the case of text printing, the frequenciesof use of C, M, and Y inks are low. Moreover, the dot density is high inthe image region and low in the character region. When all the nozzlesare used to print out an image of one sheet of paper (one page), it ispossible to reduce clogging of nozzle. Furthermore, as the frequency ofuse of each nozzle increases, clogging of each nozzle may be furtherreduced.

That is, it is better to use the nozzles as much as possible and toincrease the frequency of use of each nozzle when an image of one sheetof paper (one page) is printed. Specifically, as the number of dots usedfor printing in a direction perpendicular to a printing direction(nozzle array direction) is large, the frequency of use of each nozzleincreases. Taking the above fact into consideration, for grouping piecesof print form data, first, a score is given to each image region andeach character region that are set in a large number of pieces of printform data prepared in advance.

In the present embodiment, in association with dot density, each of theimage regions is given a score of one point per a vertical length of 2[cm] by a horizontal length of 1 [cm], and each of the character regionsis given a score of one point per a vertical length of 8 [cm] by ahorizontal length of 1 [cm]. Then, as shown by the dotted line in FIG.15, an image forming region (printing region) is divided into quarters.By using two adjacent regions among the quartered regions, the imageforming region is separated into three regions, which are a left region,a center region and a right region, as shown in FIG. 15.

For example, in the case of a print form (layout content) shown in FIG.15, when the image forming region is divided into three regions and thena score is given to each of the regions as in the manner describedabove, the left region gets “(6÷2)×8.5+16÷8)×9=43.5 [points]”, thecenter region gets “(6÷2)×9+16÷8)×10=47 [points]”, and the right regiongets “(6÷2)×8.5+16÷8)×10=43.5 [points]”. In addition, for example, inthe case of a print form (layout content) shown in FIG. 16, when theimage forming region is divided into three regions and then a score isgiven to each of the regions as in the manner described above, the leftregion gets “0+(21÷8)×9=23.625 [points], the center region gets“(6÷2)×4×2+(21÷8)×5+(7÷8)×5=41.5 [points], and the right region gets”(6÷2)×8.5×2+(7÷8)×5=55.375 [points].

As shown in the example of FIG. 16, the score of the left region inwhich the character region occupies a relatively large area is less thana half of the score of the right region in which the image regionoccupies a relatively large area. That is, in the case of printing thatuses four color CMYK inks, because the character region substantiallyuses only K ink, the frequencies of nozzle usage with respect to CMYKink colors are determined to be low (a score is set to be lower).

When a score is given to all of the pieces of print form data preparedin advance in accordance with the above manner, a distribution(deviation) of ink usage frequencies for all the nozzles used on eachpiece of print form data may be obtained. Specifically, by setting athreshold value, a determination is made by comparing the thresholdvalue with the frequency of use of each region. For example, in printingthat uses four color CMYK inks, the threshold value is set to 30 pointsand then is compared with the score of each region. In the first exampleshown in FIG. 15, because the scores of all of the regions are higherthan 30 points, it is determined that the piece of print form data givesuniform frequencies of use in all the nozzles. In addition, in thesecond example shown in FIG. 16, because only the score of the leftregion is lower than 30 points, it is determined that the piece of printform data gives the frequencies of nozzle usage that are deviated to theright region.

In addition, in the case of printing that uses three color CMY inks,because C, M, and Y inks are also used to perform printing in thecharacter region, in this case, the threshold value for scoring is, forexample, set to 20 points. By decreasing the threshold value as comparedto the case of four CMYK colors used as described above, because thescores of all the regions are larger than 20 points, for example, in thesecond example shown in FIG. 16, it is determined that the frequenciesof nozzle usage on this piece of print form data are uniform in all thenozzles. By managing a distribution of the frequencies of nozzle usageusing the scores as in the manner described above, even when CMY and Kare separated, it is possible to manage the frequencies of nozzle usagein the same manner as the one that does not separate CMY from K.

Furthermore, FIG. 18 is a view that shows an example of the results whenthe pieces of print form data of layout contents shown in the examples 1to 8 in FIG. 17 are grouped in such a manner that a score is given toeach region of each of the pieces of print form data and then adetermination is made to each of the regions defined in each of theexamples 1 to 8. In FIG. 18, the symbol “x” in the column of each regionrepresents that the score of that region is lower than the thresholdvalue, and the symbol “0” represents that the score of that region isequal to or higher than the threshold value. In addition, in the columnof grouping, “RIGHT” indicates the group of which the frequencies ofnozzle usage are deviated to the right region, “LEFT” indicates thegroup of which the frequencies of nozzle usage are deviated to the leftregion, and “UNIFORMITY” indicates the group of which the frequencies ofnozzle usage are uniform over all the printing region.

In addition, “EXCLUDED” in the column of grouping indicates a piece ofprint form data, for which it is determined to be desirably excluded,because the ink usage frequencies are low over all the regions (thescores are smaller than the threshold value) or the ink usagefrequencies of at least anyone of the regions are extremely high or low.That is, because nozzles tend to be easily clogged when the ink usagefrequencies are extremely low and also it is not preferable when thefrequencies of use are extremely high, pieces of print form data of theabove layout contents are excluded from the print form data storageportion 33.

The pieces of print form data that are grouped as shown in FIG. 18 aregrouped into three groups, which are “TO LEFT”, “UNIFORM”, and “TORIGHT”, as shown in FIG. 19A, according to a distribution of thefrequencies of nozzle usage. The thus grouped pieces of print form dataare stored in the print form data storage portion 33 according to thecontent of usage.

Note that the example shown in FIG. 19A shows an example of groupingwhen four color CMYK inks are grouped together; however, when threecolor CMY inks and K ink are separated, a group configuration will bethe one shown in FIG. 19B. That is, as shown in FIG. 19B, pieces ofprint form data are grouped into two groups: a group corresponding tothree color CMY inks and a group corresponding to K ink. Next, the groupcorresponding to three color CMY inks is grouped into three groups,which are “TO LEFT”, “UNIFORMITY”, and “TO RIGHT”, according to adistribution of the frequencies of nozzle usage. On the other hand,similarly, the group corresponding to K ink is grouped into threegroups, which are “TO LEFT”, “UNIFORMITY”, and “TO RIGHT”, according toa distribution of the frequencies of nozzle usage.

Note that all pieces of print form data are grouped according to thecontent of usage, and the example shown in FIG. 19A and the exampleshown in FIG. 19B each correspond to a piece of print form data of acertain content of usage. Next, grouping of pieces of printing elementdata corresponding to an image region will be described with referenceto FIG. 20A to FIG. 20B. Here, FIG. 20A is a view that shows therelationship between a piece of printing element data corresponding toan image region and the frequency of use of nozzles corresponding toeach ink color, and FIG. 20B is a view that shows a group configurationof pieces of printing element data corresponding to an image region whengrouping is performed on the basis of the relationship of FIG. 20A.

First, in grouping pieces of printing element data (for example,advertisement image data, or the like) corresponding to the imageregion, the frequencies of use of nozzles corresponding to each colorused to print out an image of each piece of printing element data areextracted and then the most frequently used ink color is associated withthat piece of printing element data. For example, when the print headused for printing is compatible with four CMYK ink colors, thepercentage of C used, the percentage of M used, the percentage of Y usedand the percentage of K used for each piece of printing element data areextracted as shown in FIG. 20A. Specifically, by obtaining projectioninformation through color conversion of each piece of printing elementdata, the percentages of use of nozzles of ink colors corresponding toeach piece of printing element data are extracted.

Then, as shown in the association column shown in FIG. 20A, the mostfrequently used ink color is associated with a serial number(hereinafter, referred to as object number) that is associated with eachpiece of printing element data corresponding to the image region. Inthis manner, as shown in FIG. 20B, pieces of printing element datacorresponding to the image region are grouped into four groups, whichare “PERCENTAGE OF C USED IS HIGH”, “PERCENTAGE OF M USED IS HIGH”,“PERCENTAGE OF Y USED IS HIGH”, and “PERCENTAGE OF K USED IS HIGH”. Thethus grouped pieces of print form data are stored in the printingelement data storage portion 36 according to the content of usage.

Next, the operation of the printer 300 in a state where the pieces ofprint form data and the pieces of printing element data, which aregrouped as described above, are respectively stored in the print formdata storage portion 33 and the printing element data storage portion 36will be described with reference to FIG. 21A to FIG. 23. Note that, inthe present embodiment, information of average frequency of use ofnozzles corresponding to each ink color for each piece of print formdata (print form nozzle information) is assigned to each piece of printform data.

FIG. 21A is a view that shows an example of dividing of a printingregion in a process to recognize the frequencies of nozzle usage, andFIG. 21B is a view that shows an example of a moving average that isobtained for each divided region shown in FIG. 21A. FIG. 22 is a viewthat shows a first example of the relationship between a piece of printform data and an average value of nozzle usage frequencies. FIG. 23 is aview that shows a second example of the relationship between a piece ofprint form data and an average value of nozzle usage frequencies.

When usage information corresponding to a selection instruction from aprint instruction device (not shown), or the like, is input, the usageinformation input portion 10 (see FIG. 1), in the printer 300, outputsthe input usage information to the nozzle usage frequency recognitionportion 30 (“Yes” in step 8400 in FIG. 13). Here, the usage informationincludes an instruction to print out two copies of a pay slip. Inaddition, an input process of usage information and an output process ofinput usage information are performed in such a manner that an exclusiveprogram stored in the ROM 64 is loaded onto the RAM 62, and the loadedprogram is executed by the CPU 60.

The nozzle usage frequency recognition portion 30 (see FIG. 12), whenusage information is input from the usage information input portion 10(see FIG. 12), executes a process to recognize the frequencies of use ofnozzles in a past predetermined period (step 8402 of FIG. 13). Note thatthe process to recognize nozzle usage frequencies is performed in such amanner that an exclusive program stored in the ROM 64 is loaded onto theRAM 62 and then the loaded program is executed by the CPU 60.

The nozzle usage frequency recognition portion 30 acquires nozzle usagefrequency information for a piece of print form data that has beenprinted in a past predetermined period (for example, past ten seconds,or the like) from the nozzle usage frequency information storage portion31 (step 8500 in FIG. 14). When the nozzle usage frequency has beenacquired, the printing region (image forming region) is divided intothree regions (1) to (3) as shown in FIG. 21A (step 8502 in FIG. 14),and then, for each region, the total value of the frequencies of nozzleusage in the predetermined period is calculated. When the total valueshave been calculated, the average value of the frequencies of nozzleusage corresponding to each region is calculated (step 8504 in FIG. 14).In this manner, the average value (moving average value) of nozzle usagefrequencies in each region in a past predetermined period is calculated.

Note that the regions (1) to (3) respectively correspond to the leftregion, the center region, and the right region into which the abovepieces of print form data are grouped. Subsequently, each of the movingaverage values in the above three regions is compared with a thresholdvalue that is set in advance (step S506 in FIG. 14), and, on the basisof the result of comparison, the frequencies of nozzle usage in a pastpredetermined period are recognized as three groups “TO LEFT”,“UNIFORMITY”, and “TO RIGHT” (step S508 in FIG. 14).

Specifically, when only the moving average value of the region (1) islower than the threshold value, it is recognized as “TO LEFT”, only themoving average value of the region (2) is lower than the thresholdvalue, it is recognized as “TO RIGHT”, and, when the moving averagevalues of all the regions are lower than the threshold value, it isrecognized as “UNIFORMITY”. In this manner, when the nozzle usagefrequencies in a past predetermined period have been recognized, a groupof pieces of print form data according to the recognized content isselected from the print form data storage portion 33 (step S404 in FIG.13). Note that the process to select a group of pieces of print formdata is performed in such a manner that an exclusive program stored inthe ROM 64 is loaded onto the RAM 62 and then the loaded program isexecuted by the CPU 60. Specifically, the pieces of print form data are,as described above, grouped into three groups, which are “TO LEFT”,“UNIFORMITY”, and “TO RIGHT”, according to the content of usage, so thatthe group that coincides with the above recognized content (“TO LEFT”,“UNIFORMITY”, or “TO RIGHT”) is selected.

For example, when the recognized content is “TO RIGHT”, a group ofpieces of print form data that are grouped into “TO RIGHT” is selected.When the group of piece of print form data has been selected, the printform data selection portion 34 subsequently selects a piece of printform data used for printing from the selected group in accordance withthe set selection mode.

Here, the random selection mode is set. In addition, each piece of printform data includes layout content information that includes layoutcondition information. Each piece of print form data is associated withfifth searching information that includes information of a usage contentnumber, a group number, a specific form number, the storage address ofprint form data, and is stored in the print form data storage portion33. When the random selection mode is set (“Yes” in step S406 in FIG.13), the print form data selection portion 34 first generates a randomnumber for selecting a piece of print form data by a known MT method andsearches the piece of fifth searching information having a specific formnumber that is equal to the generated random number from the selectedgroup of pieces of print form data. Note that the process to select apiece of print form data is performed in such a manner that an exclusiveprogram stored in the ROM 64 is loaded onto the RAM 62 and then theloaded program is executed by the CPU 60 (this also applies to stepsS408 and S420).

Then, the print form data selection portion 34 reads out (selects) apiece of print form data stored in the address included in the fifthsearching information that is retrieved through the above searching fromthe print form data storage portion 33 (step S408 in FIG. 13). In thismanner, for example, it is assumed that the piece of print form datashown in FIG. 22 has been selected. In FIG. 22, the graph shown on thelower side to the print form image is made so that the average value ofnozzle usage frequencies is graphed for each ink color when a printingelement corresponding to each piece of information of layout content isinserted into the print form image. However, in calculating thefrequencies of use, the average values of the frequencies of use for allpieces of insertable printing element data stored in the printingelement data storage portion 36 are used.

When the piece of print form data has been selected as described above,the printing element data selection portion 35 subsequently executes aprocess to select a piece of printing element data in accordance withthe random selection mode that is the same as the mode selecting thepiece of print form data. The printing element data selection portion 35first recognizes an ink color that is lower in frequencies of nozzleusage among pieces of print form data that belong to the selected group“TO RIGHT” on the basis of print form nozzle information assigned to theselected piece of print form data. The graph on the lower side of FIG.22 shows that, in the selected piece of print form data, the frequencyof K ink used in the right region (region (2)) is lower than thefrequencies of C, M, and Y inks used.

In such a case, the printing element data selection portion 35, whenselecting a piece of printing element data for each image regionarranged in the right region of the print form data, first selects agroup of pieces of printing element data of which the percentage of Kink used is high (percentage of K used is high) from a group of piecesof printing element data corresponding to the content of usage of printform data and the attribute (image region) indicated by information oflayout content of each selected target. Then, in regard to the selectedgroup, a random number is generated by a known MT method, and a piece ofprinting element data having an object number that is equal to therandom number is searched from the group of which the percentage of Kused is high, and then a piece of printing element data retrievedthrough the above searching is read out (selected) from the printingelement data storage portion 36 (step 8410).

On the other hand, the printing element data selection portion 35generates a random number by a known MT method for each piece ofprinting element data corresponding to the character region, searches apiece of printing element data having the same number as the randomnumber from among multiple types of pieces of printing element datacorresponding to the content of usage of the piece of print form data,and reads out (selects) the piece of printing element data retrievedthrough the above searching from the printing element data storageportion 36 (step 8410 in FIG. 13). Note that the process to select apiece of printing element data is performed in such a manner that anexclusive program stored in the ROM 64 is loaded onto the RAM 62 andthen the loaded program is executed by the CPU 60 (this also applies tostep 8422 in FIG. 13).

On the other hand, when the set selection mode is the sequentialselection mode (“No” in step 8406 in FIG. 13), the print form dataselection portion 34 selects a piece of print form data from theselected group of pieces of print form data in a predetermined sequence(step 8420 in FIG. 13). Then, similarly, for printing element data aswell, the printing element data selection portion 35 selects a piece ofprinting element data from the group of pieces of printing element dataselected on the basis of print form nozzle information in a sequencethat is determined in advance (step 8422 in FIG. 13). For example, theselection may be made in a sequence (descending sequence or ascendingsequence) of serial numbers that are associated with pieces of printform data and pieces of printing element data.

When the piece of printing element data corresponding to the selectedpiece of printing form data has been selected, the printing element datainsertion portion 15 subsequently inserts the selected piece of printingelement data into the selected piece of print form data on the basis ofinformation of layout content that is set in each selected piece ofprint form data (step 8412 in FIG. 13). Note that the process to inserta piece of printing element data is performed in such a manner that anexclusive program stored in the ROM 64 is loaded onto the RAM 62 andthen the loaded program is executed by the CPU 60.

Specifically, into each character region and image region of layoutpositions indicated by the layout content information, pieces ofprinting element data that are selected in correspondence with theseregions are inserted to thereby form a piece of image data correspondingto one sheet of paper. The print data generating portion 16 converts thegenerated sheet of piece of print form data into data that representon/off of each pixel to thereby generate print data of a format that maybe interpreted by the printing portion 17 (step 8414 in FIG. 13). Notethat the process to generate print data is performed in such a mannerthat an exclusive program stored in the ROM 64 is loaded onto the RAM 62and then the loaded program is executed by the CPU 60.

When the print data have been generated, the printing portion 17 printsout an image that is formed by the inserted printing elements on aprinting medium on the basis of the 102 above print data (step 5416 inFIG. 13). Note that the printing process is performed in such a mannerthat an exclusive program stored in the ROM 64 is loaded onto the RAM62, the loaded program is executed by the CPU 60, and then the outputdevice 72 (printing portion 17) is controlled on the basis of printcontrol signals from the CPU 60.

In the meantime, when the first piece (first sheet) of print data hasbeen generated, the nozzle usage frequency calculation portion 37calculates the frequencies of nozzle usage for the print data, andstores information of the calculated nozzle usage frequencies (nozzleusage frequency information) in the nozzle usage frequency informationstorage portion 31. Note that the process to calculate nozzle usagefrequency information is performed in such a manner that an exclusiveprogram stored in the ROM 64 is loaded onto the RAM 62 and then theloaded program is executed by the CPU 60.

Here, because the number of prints specified in the usage information istwo, for the second piece of print data, the nozzle usage frequencies ina past predetermined period is recognized using the nozzle usagefrequency information for the first piece of print data, and then agroup of pieces of print form data is selected on basis of thisrecognized content. Thereafter, as in the case of the above, a series ofprocesses is performed and then the second piece of print data isprinted. For example, it is assumed that, owing to the first print,portions that are short of nozzle usage frequencies (the frequencies ofuse of nozzles in the right region) are compensated, and thereby thefrequencies of use are uniform over all the nozzles. In this case, as asecond piece of print form data, for example, a piece of print form datathat belongs to a group of which the frequencies of use of nozzles are“UNIFORMITY” as shown on the lower side of FIG. 23 is selected.

As described above, the printer 300 according to the second embodimentis able to recognize nozzle usage frequencies in a past predeterminedperiod using the nozzle usage frequency recognition portion 30, and isable to select a group of pieces of print form data corresponding to therecognized content of nozzle usage frequencies in a past predeterminedperiod from multiple types of groups of pieces of print form data, forwhich information of layout content is set in advance and which aregrouped in accordance with distribution information of nozzle usagefrequencies, using the print form data group selection portion 32 foreach print of the specified number of prints according to the content ofusage.

In addition, the printer 300 is able to select, using the print formdata selection portion 34, a piece of print form data, used forprinting, from the selected group of pieces of print form data inaccordance with the selection mode that is set in advance. Moreover, theprinter 300 is able to select a group of pieces of printing element datacorresponding to the selected piece of print form data from amongmultiple types of groups of pieces of printing element data that aregrouped in accordance with nozzle usage frequencies according to thecontent of usage and is able to select a piece of printing element datathat is inserted into the piece of print form data from the selectedgroup in the same mode as the selection mode set in the print form dataselection portion 34 using the printing element data selection portion35.

Yet furthermore, the printer 300 is able to insert, using the printingelement data insertion portion 15, the selected piece of printingelement data into the selected piece of print form data, and then isable to generate, using the print data generating portion 16, print datafrom the piece of print form data, into which the selected piece ofprinting element data has been inserted. Then, the printer 300 is ableto print out, using the printing portion 17, an image on the basis ofthe print data. As described above, because, for each print, thefrequencies of use of nozzles in a past predetermined period arerecognized, a piece of print form data that uses nozzles of which thefrequencies of use are low is selected and then an image may be printed,it is possible to accurately improve the frequencies of use of nozzlesof the print head 200 (reduce nozzles that are not used).

In the second embodiment, the nozzle usage frequency recognition portion30, the print form data group selection portion 32 and the print formdata selection portion 34 may be regarded as the print form dataselection unit of the third or sixth aspect, the print form data storageportion 33 may be regarded as the print form data storage unit of anyoneof the third, sixth, ninth and eleventh aspects, the printing elementdata selection portion 35 may be regarded as the printing element dataselection unit of anyone of the third, fourth and seventh aspects, theprinting element data storage portion 36 may be regarded as the printingelement data storage unit of anyone of the third, seventh, ninth andeleventh aspects, the printing element data insertion portion 15 may beregarded as the printing element data insertion unit of the third orfourth aspect, and the nozzle usage frequency calculation portion 37 maybe regarded as the usage frequency calculation unit of the third aspect.

In addition, in the above second embodiment, the steps 5402 to 5408 and5420 in FIG. 13 may be regarded as the print form data selection step ofthe ninth or eleventh aspect, the steps 5410 and 5422 in FIG. 13 may beregarded as the printing element data selection step of the ninth oreleventh aspect, the step 5412 in FIG. 13 may be regarded as theprinting element data insertion step of the ninth or eleventh aspect,and the step 5418 in FIG. 13 may be regarded as the usage frequencycalculation step of the ninth or eleventh aspect.

Note that, in the above second embodiment, the print form data includelayout condition information (the second configuration in the firstembodiment); however, as in the case of the first embodiment, the layoutcondition of each printing element may be randomly selected, in additionto the configuration that the first configuration is applied and a pieceof print form data that includes a piece of information of layoutposition corresponding to the attribute of each printing element.

According to the above configuration, because a layout condition mayalso be randomly selected, it is possible to reduce storage capacity forprint form data. Note that, in the above second embodiment, the piecesof print form data are grouped in accordance with a distribution(deviation) of the frequencies of nozzle usage; however, the grouping isnot limited to this. The grouping may be performed according to afurther segmented distribution, or may be performed by another method.

In addition, in the first embodiment, layout condition information israndomly selected only for a character region; however, regions forwhich layout condition information is randomly selected are not limitedto the character regions. Layout condition information may be randomlyselected for an image region as well. The layout condition informationof an image region corresponds to, for example, information ofresolution, information of palette (limitations of color representation,and the like), information of a type of algorithm when an image isreduced or enlarged to be adjusted to the size of a layout region, andthe like.

In addition, in the first and second embodiments, the layout conditioninformation includes two types of information, which are font typeinformation and font size information; however, the layout conditioninformation is not limited to them. The layout condition information mayinclude other pieces of information, such as character alignment,character spacing, line space, and margin. Moreover, the feature of theprinter 100 according to the above first embodiment and the feature ofthe printer 300 according to the above second embodiment are is it ispossible to improve the frequencies of nozzle usage using the manner ofselection of a piece of print form data and a piece of printing elementdata without substantially adding any additional components to theexisting printer itself. Thus, it is not necessary to particularlyprovide an exclusive component as the printing portion 17, and it ispossible to use the existing ink jet printer as it is. Furthermore, whenthe printing portion 17 is separated from the printer 100 and theprinter 300 according to the above first and second embodiments, thefunctions of the printing portion 17 may be implemented by a generalpurpose print instruction terminal, such as a personal computer, aprinter server, or the like.

In addition, in the above first and second embodiments, an exclusivecomputer program stored in the ROM 64 is loaded onto the RAM 62 to beexecuted by the CPU 60; however, the configuration is not limited tothis. The programs may be installed in the storage device 70 through astorage medium, such as a CD-ROM, a DVD-ROM, a flexible disk (FD), ormay be installed in the storage device 70 through a communicationnetwork, such as the internet and then loaded onto the RAM 62 to beexecuted by the CPU 60.

1. A printer that includes a line head in which nozzles forming an imageby discharging ink are arranged in a plurality of lines, wherein theprinter prints out an image on the basis of print form data in whichinformation of layout contents of printing elements forming a content ofa print is set according to an attribute of each printing element, theprinter comprising: a print form data storage unit that stores multiplepieces of print form data, which include different layout contents ofthe printing elements according to a content of usage; a printingelement data storage unit that stores multiple types of pieces ofprinting element data, which correspond to pieces of data of theprinting elements according to the attribute of each printing element; aprint form data selection unit that selects a piece of print form data,which is used for printing, from among the multiple pieces of print formdata stored in the print form data storage unit; a printing element dataselection unit that selects a piece of printing element datacorresponding to each piece of information of layout content that is setin the selected piece of print form data from among the multiple typesof pieces of printing element data stored in the printing element datastorage unit; and a printing element data insertion unit that insertsthe selected piece of printing element data into the selected piece ofprint form data on the basis of information of the content of print,which is set in the selected piece of print form data.
 2. The printeraccording to claim 1, wherein the print form data selection unitrandomly selects the piece of the print form data, which is used forprinting, from among the multiple pieces of print form data stored inthe print form data storage unit.
 3. The printer according to claim 1,wherein the print element data selection unit randomly selects the pieceof printing element data corresponding to each piece of information ofthe layout content set in the selected piece of the print form data fromamong the multiple types of pieces of the printing element data that arestored in the printing element data storage unit.
 4. The printeraccording to claim 1, wherein the information of layout content includesinformation of layout position of each printing element and informationthat indicates a layout condition corresponding to the attribute of eachprinting element, the information of layout position corresponding toeach piece of printing element is set in advance in each piece of printform data, the printer further includes a layout condition informationstorage unit that stores multiple types of pieces of the layoutcondition information according to the attribute of each printingelement, a layout condition information selection unit that randomlyselects a piece of layout condition information of a printing elementfor information of each layout content set in the selected piece ofprint form data from among the multiple types of pieces of layoutcondition information stored in the layout condition information storageunit, and a layout condition information setting unit that sets thepiece of layout condition information, which is selected by the layoutcondition information selection unit, to the selected piece of printform data, and the printing element data insertion unit inserts thepiece of printing element data, which is selected by the printingelement data selection unit, into the piece of print form data to whichthe piece of layout condition information is set.
 5. The printeraccording to claim 1, further comprising a usage frequency calculationunit that calculates the frequencies of use of the nozzles on the basisof the piece of print form data, into which the piece of the printingelement data has been inserted and which has been printed before,wherein the print form data storage unit that stores the multiple piecesof the print form data, according to the content of the usage and inassociation with print form nozzle information that is informationregarding the frequencies of the use of the nozzles when printing isperformed on the basis of the print form data, and the print form dataselection unit that selects the piece of the print form data on thebasis of the calculated frequencies of the use from among the multiplepieces of the print form data that are stored in the print form datastorage unit.
 6. The printer according to claim 5, wherein the printform nozzle information includes information that indicates adistribution of the frequencies of use of the plurality of nozzles whenprinting is performed based on the print form data.
 7. The printeraccording to claim 5, wherein the multiple pieces of print form data aregrouped into a plurality of groups according to the content of the printform nozzle information and then stored in the print form data storageunit, and wherein the print form data selection unit selects a group ofpieces of print form data on the basis of the calculated frequencies ofuse from among the plurality of groups of pieces of print form data thatare stored in the print form data storage unit, and randomly selects apiece of print form data, which is used for printing, from the selectedgroup.
 8. The printer according to claim 7, wherein the multiple typesof pieces of printing element data are grouped into a plurality ofgroups according to a content of printing element nozzle informationregarding frequencies of use of the nozzles when an image of theprinting element data is printed and then stored in the printing elementdata storage unit, and the printing element data selection unit selectsa group of printing element data for each piece of information of layoutcontent set in the selected piece of print form data based on calculatedfrequencies of use from among the multiple types of pieces of printingelement data stored in the printing element data storage unit for eachlayout content, and randomly selects a piece of printing element datafor each layout content from each selected group.
 9. A printing systemthat controls a printer that includes a line head in which nozzles thatform an image by discharging ink are arranged in a plurality of lines,wherein the printer prints out an image on the basis of print form datain which information of layout contents of printing elements that form acontent of print is set according to an attribute of each printingelement, wherein the printing program is used to execute a process on acomputer, the system comprising: a printing form data selecting unitthat selects a piece of print form data, which is used for printing, onthe basis of the calculated frequencies of use from among multiplepieces of print form data that are stored in a print form data storageunit that stores the multiple pieces of print form data, which includedifferent layout contents of the printing elements, according to thecontent of usage and in association with print form nozzle informationthat is information regarding the frequencies of use of the nozzles whenprinting is performed based on the print form data; a printing elementdata selecting unit that selects a piece of printing element data foreach piece of information of layout content that is set in the selectedpiece of print form data from among multiple types of pieces of printingelement data stored in a printing element data storage unit that storesthe multiple types of pieces printing element data, which correspond topieces of data of the printing elements, according to the attribute ofeach printing element; and a printing element data inserting unit thatinserts the selected piece of printing element data into the selectedpiece of print form data based on information of the content of print,which is set in the selected piece of print form data.
 10. A printingsystem comprising: a printing unit that includes a line head in whichnozzles that form an image by discharging ink are arranged in aplurality of lines; a print form data storage unit that stores multiplepieces of print form data; and a print form data selecting unit thatselects a piece of print form data which is used for printing, from themultiple pieces of the print form data stored in the print form a datastorage unit, the printing unit printing each piece of information ofcontent that is set in the selected piece of the print form data.